* Added groups as Binding attr for easy groups_names definition
* Binding: inbound - updating fields that only in fields attribute
* Added tests for inbound part of binding #343
* Fix for flake8 checker
* Revert "Added groups as Binding attr for easy groups_names definition"
This reverts commit 009b4adbee534d4ccbea191ce2523a0edb09d407.
* Using group_names at inbound tests
* fixed usage of group_names in *_change_receiver
group_names was missing second arg (action)
* fixed group_names to include action
* made group_names a classmethod
* Implement the data binding behaviour from Django DDP.
Correct dispatch of create/update/delete according to how group_names change
when compared between pre and post save/delete.
* Fix tests for databinding improvements.
