Automatically override ModelForm automatic form fields with the floppy equivalents.
Resolves #63.
Added workarounds for django < 1.6.
Moved new ModelForm behavior into floppyforms/__future__
Added tests of __future__ functionality.
Added __future__ note to docs.
Disabled flake8 qa of floppyforms/__future__/__init__.py
Moving tests of ModelForm field setting to an extra test file and simplifying the test cases.
Adding FutureWarning that ModelForm behaviour will change in next floppyforms version.
Fixing issue with Django <1.7 where ALL_FIELDS constant does not exist.
Ignore flake8 checking on floppyforms.__future__.models module.