Fixed #23856 -- Warned about downloading development version

Replicated the warning from
https://docs.djangoproject.com/en/1.7/intro/install/ about how the
development version is best used by those with experience looking to
test.
Removed unused file: accounts/profile_urls.py
Updated to Django 1.7

-Replaced south migrations with built-in migrations.
-Updated to use django-registration-redux.