Add multiple trash can support, restoring and complete source object manager and queryset method substitution

apps/common/querysets.py

@@ -0,0 +1,14 @@
+from __future__ import absolute_import
+
+from django.db.models.query import QuerySet
+
+from .managers import CustomizableQuerySetManager
+
+
+class CustomizableQuerySet(QuerySet):
+    """Base QuerySet class for adding custom methods that are made
+    available on both the manager and subsequent cloned QuerySets"""
+
+    @classmethod
+    def as_manager(cls, ManagerClass=CustomizableQuerySetManager):
+        return ManagerClass(cls)