added initial proof of concept for Django sessions in login

not working yet
added a bound form when trying to log in users
navigating to users index now displays information about whether you're logged in
blocked out methods for testing logging in and logging out
removed join date field on users
added test for authenticating user
added tests for logging in with wrong username or password
now actually testing whether a user logs in successfully
updated other login/out tests to actually work
now User is subclass of django.auth AbstractBaseUser
added custom UserManager and fixed references in code to username field
authentication now working, tests don't pass

User model updated to have necessary fields;
Custom backend to handle authentication with email;
Tests need to be updated to test login properly
Using User.objects.create_user instead of User.objects.create()
login and logout tests now passing
removed south migrations from version control
changed names of login and logout views
more changes, some things broken
update register and login views and tests

changed urls for log in/out and register to be top level
wrote test for registering new user and made it pass
updated register template to add required fields