Django 1.7 support

Initial support for django 1.7. Fixes #134
You will have a really hard time if you target both 1.6 and 1.7 compatibility with the same code base, because 1.7 is fundamentally sooo different. It would be very hard to develop for this kind of app. I suggest ditch 1.6 and make a new fork which focuses 1.7 only. This way you can use the new features of Django and develop it much faster. It will be easier.
This repo has good support for 1.6 and will be maintained for a long time. Don't overcomplicate things!