Add support for custom Django User models.

Try importing user model with django.contrib.auth.get_user_model(),
and fallback to django.contrib.auth.User on ImportError. This adds
support for custom user models, supported by newer Django releases.

Patch by Niels Poppe <nlsp@xs4all.nl>.

Signed-off-by: Ville Korhonen <ville@xd.fi>
Bump version number.
Add EditorConfig configuration file.
Fix syntax: remove invalid whitespaces.
Add missing docstring.
Ignore Vim swapfiles.
Remove obsolete TODO note.
Fix whitespaces.
Fix syntax: remove extra whitespaces.
Disable unreachable code.
Fix syntax: whitespaces.
Merged support for custom user models.