Support swappable user models.

Refs #143.
Merge branch 'django-1.5'
Migrate to the new graph_auth directory
Merge pull request #215 from Pirhoo/patch-1

Migrate to the new graph_auth directory
Merge pull request #1 from scholrly/master

Merge new graph_auth
Corrected 'my_model' to 'my_app' in auth.rst.
Need django.contrib.auth.models.User's get_username method

Sometimes it throws an exception.
With a grep I see it's needed in admin interface too.
Update auth.rst
Merge pull request #216 from tonjo/master

Small updates
backend fix
backends complete fix
Backend fix
test_settings fix
Disable case sensitive in ORDER BY clause

This simple addition makes "order by" case insensitive (which is the default behavior with other Django db backends ;).
Merge pull request #220 from Pirhoo/patch-2

Disable case sensitive in ORDER BY clause
Moved LOVER function to orderby expression
Remove lower
Merge pull request #221 from Pirhoo/patch-2

Removed lowercase on Order By
Merge branch 'master' of https://github.com/scholrly/neo4django
We don't yet support Django 1.6+.