added South migration support
Added enum param could be string (to support south)
added serialization support
enabled proper integer serialization.
added default field converter
fixed default values and added test coverage
rebase
updated version
fixed tests
enabled support for default=None
version bump
restored Python3 support
Merge branch 'south'

* south:
  restored Python3 support
  version bump
  enabled support for default=None
  fixed tests
  updated version
  rebase
  fixed default values and added test coverage
  added default field converter
  enabled proper integer serialization.
  added serialization support
  Added enum param could be string (to support south)
  added South migration support