Python 3.3 and Django 1.5.4 compatibility.

Hello mate,

I have upgraded ``django-dfk`` to be compatible with Python 3.3 and fixed it to work on the most recent stable version of Django. (1.5.4 at time of pull request).

Test suite passes 100% and I have PEP8'd the code base for you.

Please review the changes and let me know if there is anything else you would like me to do in order to get this merged. :)

Thanks a lot,
Rob