Some PEP 8 cleanup
Migrated get_dirty_fields to a property named dirty_fields
Removed Django as a requirement. Django is implied in the name, and its inclusion can lead to unexpected behavior in projects.
Updated the __init__.py to include version tracking and a description
Moved the dirtyfields package out of src
Example App's settings now adds the dirtyfields package to its path.
Double checking that the field is not being added when setting the "update_fields" kwarg in Django 1.5
Updated tests and made sure they work
Updated the README
Minor updates to setup for packaging