Profile and group refactor

This includes all **server side** changes necessary for the implementation of user profiles and improved study session descriptions. 

**IMPORTANT** These changes affect the data model associated with our application. As a result, I have pushed changes to settings.py to activate a local database. To set up the local database when you pull, please follow these steps:

1. Run `python manage.py syncdb` and select `no` when prompted to create a superuser.
2. Run `python manage.py shell < ./scripts/populate_database.py` to add a university to your database
3. Run `python manage.py shell < ./scripts/add_course.py` to add a course to your database
4. Run `python manage.py get_uvic_building_info uvic_building_info.csv` to add UVic building information to your database.
5. You should now be able to sign up and test everything as usual. 

If you have any questions/comments/concerns, please leave them as comments on this pull request and I'll address them ASAP.