Return unicode from _unicode_ methods

Import from PyCon improvement.

Author: Dan Poirier <dpoirier@caktusgroup.com>
Date: Mon Jul 8 15:55:33 2013 -0400

Return unicode from __unicode__ methods

Signed-off-by: Hiroshi Miura <miurahr@linux.com>

Remove migrations

These migrations were written for South. Now that we have Django 1.7,
we will just use Django migrations once we hit a 1.0 release.