Update Python/Django

[ghost]

Brings all dependency versions up-to-date. Drops the dependency on django-pagination which is not compatible with Python 3. Test suite runs against 4 environments:

• Django 1.7 and Python 3.4
• Django 1.7 and Python 2.7
• Django 1.6 and Python 3.3
• Django 1.6 and Python 2.7

Also brought all files into compliance with Flake8. I added a requirement to the build that Flake8 pass for each environment.

Still need to update the README and complete internal regression testing.

[ghost]

Thanks for the many comments @dpoirier. I've updated the pull request.

[dpoirier]

:sunglasses:

[ghost]

Thanks for noticing. I also just restored the old migrations in south_migrations/ directories for Django 1.6.

[dpoirier]

:sunglasses:

[ghost]

Merging this to develop for internal regression testing before release.