GitLab

This implements the model, admin, and LDAP export.  Still no user
interface.

- rstrip() is not the right function to use
- __file__ can end in ".pyc", not just ".py"
- remove an additional '.' to have a correct module path at the end

+ LDAP_ACTIVATE doc was just irrelevant, default already being `False`.

Documents how to enable it.

fix #52

This conforms to the "new" Django organisation: Django apps live outside
of the Django project.  Also, it is more logical because the VPN
application should be optional in Coin.

This change is necessary to be able to use Django's application features
https://docs.djangoproject.com/en/1.7/ref/applications/

(see #57 for details)