Added missing file “workflows_tags.py”
Improve State models:
- added 'codename' field
- added 'description' field
- added 'state_position' field (requires django-positions) to optionally list all states of a specific Workflow in arbitrary order
TransitionObjectRelation model added to optionally keep track of workflow history of every object; specify the optional parameter "user" in set_state() in order to record the transition
unit tests updated to take into account the uniqueness of new State.codename attribute
optional “direction” flag added to Transition
Improved admin