Authentication

#### Connect users to lists
This will make a list url return 404 if the one requesting it is not logged inn as the right user.

#### General auth
Settings option `PERACTO_USE_AUTH` will make all views except index demand a user to be authenticated. `peracto.decorators.peracto_login_required` is very similar to the django `@login_required` except it only checks if `PERACTO_USE_AUTH = True`.