merge with gn's code

34 files changed, 210 insertions, 42 deletions

diff --git a/gstudio/admin/attribute.py b/gstudio/admin/attribute.py
index 31266c4..20dcfd9 100644
--- a/gstudio/admin/attribute.py
+++ b/gstudio/admin/attribute.py
@@ -7,8 +7,14 @@ from gstudio.admin.forms import AttributeAdminForm
 from gstudio.models import *
 import reversion
 from django.template.defaultfilters import slugify
+from gstudio.settings import GSTUDIO_VERSIONING
 
-class AttributeAdmin(reversion.VersionAdmin):
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
+
+class AttributeAdmin(parent_class):
     fieldsets=((_('Attribute'),{'fields': ('attributetype','attributetype_scope','subject','subject_scope','svalue','value_scope')}),
 
 )
diff --git a/gstudio/admin/attribute_bigintegerfield.py b/gstudio/admin/attribute_bigintegerfield.py
index 53085fb..277623f 100644
--- a/gstudio/admin/attribute_bigintegerfield.py
+++ b/gstudio/admin/attribute_bigintegerfield.py
@@ -1,9 +1,13 @@
 from django.contrib import admin
 from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
+from gstudio.settings import GSTUDIO_VERSIONING
 
 from gstudio.admin.forms import AttributeBigIntegerFieldAdminForm
 import reversion
-
-class AttributeBigIntegerFieldAdmin(reversion.VersionAdmin):
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+   parent_class = admin.ModelAdmin
+class AttributeBigIntegerFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_booleanfield.py b/gstudio/admin/attribute_booleanfield.py
index e6ce41f..17c3efe 100644
--- a/gstudio/admin/attribute_booleanfield.py
+++ b/gstudio/admin/attribute_booleanfield.py
@@ -3,7 +3,11 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeBooleanFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
-
-class AttributeBooleanFieldAdmin(reversion.VersionAdmin):
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
+class AttributeBooleanFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_charfield.py b/gstudio/admin/attribute_charfield.py
index 138d89d..6f41aa4 100644
--- a/gstudio/admin/attribute_charfield.py
+++ b/gstudio/admin/attribute_charfield.py
@@ -1,10 +1,14 @@
 from django.contrib import admin
 from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
-
+from gstudio.settings import GSTUDIO_VERSIONING
 from gstudio.admin.forms import AttributeCharFieldAdminForm
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeCharFieldAdmin(reversion.VersionAdmin):
+class AttributeCharFieldAdmin(parent_class):
     pass
  
diff --git a/gstudio/admin/attribute_commaseparatedintegerfield.py b/gstudio/admin/attribute_commaseparatedintegerfield.py
index 4202f61..c3701d9 100644
--- a/gstudio/admin/attribute_commaseparatedintegerfield.py
+++ b/gstudio/admin/attribute_commaseparatedintegerfield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeCommaSeparatedIntegerFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeCommaSeparatedIntegerFieldAdmin(reversion.VersionAdmin):
+class AttributeCommaSeparatedIntegerFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_datefield.py b/gstudio/admin/attribute_datefield.py
index 9619547..b62d2ca 100644
--- a/gstudio/admin/attribute_datefield.py
+++ b/gstudio/admin/attribute_datefield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeDateFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeDateFieldAdmin(reversion.VersionAdmin):
+class AttributeDateFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_datetimefield.py b/gstudio/admin/attribute_datetimefield.py
index bdbdfa5..74bc7ca 100644
--- a/gstudio/admin/attribute_datetimefield.py
+++ b/gstudio/admin/attribute_datetimefield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeDateTimeFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeDateTimeFieldAdmin(reversion.VersionAdmin):
+class AttributeDateTimeFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_decimalfield.py b/gstudio/admin/attribute_decimalfield.py
index 168ad06..9c9dd96 100644
--- a/gstudio/admin/attribute_decimalfield.py
+++ b/gstudio/admin/attribute_decimalfield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeDecimalFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeDecimalFieldAdmin(reversion.VersionAdmin):
+class AttributeDecimalFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_emailfield.py b/gstudio/admin/attribute_emailfield.py
index 8173f2c..a69196a 100644
--- a/gstudio/admin/attribute_emailfield.py
+++ b/gstudio/admin/attribute_emailfield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeEmailFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeEmailFieldAdmin(reversion.VersionAdmin):
+class AttributeEmailFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_filefield.py b/gstudio/admin/attribute_filefield.py
index a2553c6..11b90e4 100644
--- a/gstudio/admin/attribute_filefield.py
+++ b/gstudio/admin/attribute_filefield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeFileFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeFileFieldAdmin(reversion.VersionAdmin):
+class AttributeFileFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_filepathfield.py b/gstudio/admin/attribute_filepathfield.py
index 76d483d..c65346d 100644
--- a/gstudio/admin/attribute_filepathfield.py
+++ b/gstudio/admin/attribute_filepathfield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeFilePathFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeFilePathFieldAdmin(reversion.VersionAdmin):
+class AttributeFilePathFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_floatfield.py b/gstudio/admin/attribute_floatfield.py
index 0f97b7c..1563f92 100644
--- a/gstudio/admin/attribute_floatfield.py
+++ b/gstudio/admin/attribute_floatfield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeFloatFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeFloatFieldAdmin(reversion.VersionAdmin):
+class AttributeFloatFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_imagefield.py b/gstudio/admin/attribute_imagefield.py
index 80515a6..c203e83 100644
--- a/gstudio/admin/attribute_imagefield.py
+++ b/gstudio/admin/attribute_imagefield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeImageFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeImageFieldAdmin(reversion.VersionAdmin):
+class AttributeImageFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_integerfield.py b/gstudio/admin/attribute_integerfield.py
index a170c95..b98251f 100644
--- a/gstudio/admin/attribute_integerfield.py
+++ b/gstudio/admin/attribute_integerfield.py
@@ -3,7 +3,13 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeIntegerFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeIntegerFieldAdmin(reversion.VersionAdmin):
+
+class AttributeIntegerFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_ipaddressfield.py b/gstudio/admin/attribute_ipaddressfield.py
index 1fa9a1b..05570fc 100644
--- a/gstudio/admin/attribute_ipaddressfield.py
+++ b/gstudio/admin/attribute_ipaddressfield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeIPAddressFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeIPAddressFieldAdmin(reversion.VersionAdmin):
+class AttributeIPAddressFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_nullbooleanfield.py b/gstudio/admin/attribute_nullbooleanfield.py
index fba5208..6a4d7f1 100644
--- a/gstudio/admin/attribute_nullbooleanfield.py
+++ b/gstudio/admin/attribute_nullbooleanfield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeNullBooleanFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeNullBooleanFieldAdmin(reversion.VersionAdmin):
+class AttributeNullBooleanFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_positiveintegerfield.py b/gstudio/admin/attribute_positiveintegerfield.py
index 1404449..54fd939 100644
--- a/gstudio/admin/attribute_positiveintegerfield.py
+++ b/gstudio/admin/attribute_positiveintegerfield.py
@@ -3,7 +3,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributePositiveIntegerFieldAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributePositiveIntegerFieldAdmin(reversion.VersionAdmin):
+class AttributePositiveIntegerFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_textfield.py b/gstudio/admin/attribute_textfield.py
index 7786af1..5ba20f3 100644
--- a/gstudio/admin/attribute_textfield.py
+++ b/gstudio/admin/attribute_textfield.py
@@ -4,6 +4,11 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeTextFieldAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeTextFieldAdmin(reversion.VersionAdmin):
+class AttributeTextFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_timefield.py b/gstudio/admin/attribute_timefield.py
index 929b028..c719082 100644
--- a/gstudio/admin/attribute_timefield.py
+++ b/gstudio/admin/attribute_timefield.py
@@ -4,6 +4,11 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeTimeFieldAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeTimeFieldAdmin(reversion.VersionAdmin):
+class AttributeTimeFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attribute_urlfield.py b/gstudio/admin/attribute_urlfield.py
index 952beec..75f9f80 100644
--- a/gstudio/admin/attribute_urlfield.py
+++ b/gstudio/admin/attribute_urlfield.py
@@ -4,6 +4,11 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import AttributeURLFieldAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeURLFieldAdmin(reversion.VersionAdmin):
+class AttributeURLFieldAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attributespecification.py b/gstudio/admin/attributespecification.py
index 3e7f6e1..781343b 100644
--- a/gstudio/admin/attributespecification.py
+++ b/gstudio/admin/attributespecification.py
@@ -4,7 +4,12 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _ 
 
 from gstudio.admin.forms import AttributeSpecificationAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class AttributeSpecificationAdmin(reversion.VersionAdmin):
+class AttributeSpecificationAdmin(parent_class):
     pass
diff --git a/gstudio/admin/attributetype.py b/gstudio/admin/attributetype.py
index c1f03d9..c44db82 100644
--- a/gstudio/admin/attributetype.py
+++ b/gstudio/admin/attributetype.py
@@ -20,11 +20,15 @@ from gstudio.managers import HIDDEN
 from gstudio.managers import PUBLISHED
 from gstudio.ping import DirectoryPinger
 from gstudio.admin.forms import AttributetypeAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 
 
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-
-class AttributetypeAdmin(reversion.VersionAdmin):
+class AttributetypeAdmin(parent_class):
     """Admin for Attributetype model"""
     form = AttributetypeAdminForm
     date_hierarchy = 'creation_date'
diff --git a/gstudio/admin/complement.py b/gstudio/admin/complement.py
index b35ad6c..305bb46 100644
--- a/gstudio/admin/complement.py
+++ b/gstudio/admin/complement.py
@@ -4,6 +4,11 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import ComplementAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class ComplementAdmin(reversion.VersionAdmin):
+class ComplementAdmin(parent_class):
     pass
diff --git a/gstudio/admin/expression.py b/gstudio/admin/expression.py
index a6a8fd2..cebd696 100644
--- a/gstudio/admin/expression.py
+++ b/gstudio/admin/expression.py
@@ -5,8 +5,13 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import ExpressionAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class ExpressionAdmin(reversion.VersionAdmin):
+class ExpressionAdmin(parent_class):
     def save_model(self, request, expression, form, change):
         expression.title = expression.composed_sentence
         expression.save()
diff --git a/gstudio/admin/intersection.py b/gstudio/admin/intersection.py
index 6e9dd3e..49f2c5d 100644
--- a/gstudio/admin/intersection.py
+++ b/gstudio/admin/intersection.py
@@ -4,6 +4,11 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import IntersectionAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class IntersectionAdmin(reversion.VersionAdmin):
+class IntersectionAdmin(parent_class):
     pass
diff --git a/gstudio/admin/metatype.py b/gstudio/admin/metatype.py
index bb24fc7..f110bac 100644
--- a/gstudio/admin/metatype.py
+++ b/gstudio/admin/metatype.py
@@ -5,8 +5,13 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import MetatypeAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class MetatypeAdmin(reversion.VersionAdmin):
+class MetatypeAdmin(parent_class):
     """Admin for Metatype model"""
     form = MetatypeAdminForm
     fields = ('title','altnames', 'parent', 'description', 'slug')
diff --git a/gstudio/admin/nodespecification.py b/gstudio/admin/nodespecification.py
index aaf784e..f55bd05 100644
--- a/gstudio/admin/nodespecification.py
+++ b/gstudio/admin/nodespecification.py
@@ -4,6 +4,11 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import NodeSpecificationAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class NodeSpecificationAdmin(reversion.VersionAdmin):
+class NodeSpecificationAdmin(parent_class):
     pass
diff --git a/gstudio/admin/objecttype.py b/gstudio/admin/objecttype.py
index 7440140..5072fe9 100644
--- a/gstudio/admin/objecttype.py
+++ b/gstudio/admin/objecttype.py
@@ -14,16 +14,22 @@ from django.core.urlresolvers import reverse, NoReverseMatch
 from tagging.models import Tag
 
 import reversion
+
 from gstudio import settings
 from gstudio.managers import HIDDEN
 from gstudio.managers import PUBLISHED
 from gstudio.ping import DirectoryPinger
 from gstudio.admin.forms import ObjecttypeAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 
 
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+   parent_class = admin.ModelAdmin
 
 
-class ObjecttypeAdmin(reversion.VersionAdmin):
+class ObjecttypeAdmin(parent_class):
     """Admin for Objecttype model"""
     form = ObjecttypeAdminForm
     date_hierarchy = 'creation_date'
diff --git a/gstudio/admin/processtype.py b/gstudio/admin/processtype.py
index 72a795b..1862de3 100644
--- a/gstudio/admin/processtype.py
+++ b/gstudio/admin/processtype.py
@@ -20,11 +20,14 @@ from gstudio.managers import HIDDEN
 from gstudio.managers import PUBLISHED
 from gstudio.ping import DirectoryPinger
 from gstudio.admin.forms import ProcesstypeAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 
 
-
-
-class ProcesstypeAdmin(reversion.VersionAdmin):
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
+class ProcesstypeAdmin(parent_class):
     """Admin for Processtype model"""
     form = ProcesstypeAdminForm
     date_hierarchy = 'creation_date'
diff --git a/gstudio/admin/relation.py b/gstudio/admin/relation.py
index 8f112ef..7009afb 100644
--- a/gstudio/admin/relation.py
+++ b/gstudio/admin/relation.py
@@ -6,8 +6,14 @@ from django.utils.translation import ugettext_lazy as _
 from gstudio.admin.forms import RelationAdminForm
 import reversion
 from django.template.defaultfilters import slugify
+from gstudio.settings import GSTUDIO_VERSIONING
 
-class RelationAdmin(reversion.VersionAdmin):
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
+
+class RelationAdmin(parent_class):
     fieldsets=((_('Relation'),{'fields': ('relationtype','relationtype_scope','left_subject' ,'left_subject_scope','right_subject','right_subject_scope')}),
 
 )
diff --git a/gstudio/admin/relationspecification.py b/gstudio/admin/relationspecification.py
index 5da162b..6018236 100644
--- a/gstudio/admin/relationspecification.py
+++ b/gstudio/admin/relationspecification.py
@@ -4,6 +4,12 @@ from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import RelationSpecificationAdminForm
 import reversion
+from gstudio.settings import GSTUDIO_VERSIONING
 
-class RelationSpecificationAdmin(reversion.VersionAdmin):
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
+
+class RelationSpecificationAdmin(parent_class):
     pass
diff --git a/gstudio/admin/relationtype.py b/gstudio/admin/relationtype.py
index 374f9a8..37e1a33 100644
--- a/gstudio/admin/relationtype.py
+++ b/gstudio/admin/relationtype.py
@@ -19,11 +19,15 @@ from gstudio.managers import HIDDEN
 from gstudio.managers import PUBLISHED
 from gstudio.ping import DirectoryPinger
 from gstudio.admin.forms import RelationtypeAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 
 
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-
-class RelationtypeAdmin(reversion.VersionAdmin):
+class RelationtypeAdmin(parent_class):
     """Admin for Relationtype model"""
     form = RelationtypeAdminForm
     date_hierarchy = 'creation_date'
diff --git a/gstudio/admin/systemtype.py b/gstudio/admin/systemtype.py
index 8a12856..7041db0 100644
--- a/gstudio/admin/systemtype.py
+++ b/gstudio/admin/systemtype.py
@@ -20,11 +20,15 @@ from gstudio.managers import HIDDEN
 from gstudio.managers import PUBLISHED
 from gstudio.ping import DirectoryPinger
 from gstudio.admin.forms import SystemtypeAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
 
 
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-
-class SystemtypeAdmin(reversion.VersionAdmin):
+class SystemtypeAdmin(parent_class):
     """Admin for Systemtype model"""
     form = SystemtypeAdminForm
     date_hierarchy = 'creation_date'
diff --git a/gstudio/admin/union.py b/gstudio/admin/union.py
index 0836936..d9bc092 100644
--- a/gstudio/admin/union.py
+++ b/gstudio/admin/union.py
@@ -3,7 +3,13 @@ from django.core.urlresolvers import NoReverseMatch
 from django.utils.translation import ugettext_lazy as _
 
 from gstudio.admin.forms import UnionAdminForm
+from gstudio.settings import GSTUDIO_VERSIONING
+
 import reversion
+if GSTUDIO_VERSIONING == True:
+    parent_class = reversion.VersionAdmin
+else:
+    parent_class = admin.ModelAdmin 
 
-class UnionAdmin(reversion.VersionAdmin):
+class UnionAdmin(parent_class):
     pass