Remove lint
Fix the Django Debug Toolbar
Use unique email address form for signup.

Also:
Split login/urls.py into a package and move registration urls there.
Fix running the test suite through manage.sh

Apparently the DiscoverRunner needs to be run from the project directory.

Since the Django docs generally show manage.py being used from the
directory it is in, I just changed manage.sh to always run from /opt/app
Use core.User for the auth user model.

Unique email addresses are verified in a full clean method, instead of
with `unique=True` so that we can subclass AbstractUser instead of
AbstractBaseUser.

Also adds `blank=True` to `requested_individual_mapping_at` to allow null
values to pass `full_clean`
Switch to filebased email backend for development
Remove references to site.name
PR fixup: use case insensitive match for email validation