extensions_framework: inherit property_group_renderer from bpy.types.…

…Panel, works with manual RNA registration

modules/extensions_framework/ui.py

@@ -53,7 +53,7 @@ def _get_item_from_context(context, path):
  context = getattr(context, p)
  return context
 
-class property_group_renderer(object):
+class property_group_renderer(bpy.types.Panel):
  """Mix-in class for sub-classes of bpy.types.Panel. This class
  will provide the draw() method which implements drawing one or
  more property groups derived from