django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet. when starting MAAS with Django 1.7

[Raphaël Badin]

Full stacktrace: http://paste.ubuntu.com/10589786/

This happens because the Twisted service try to use the ORM before the models are loaded (see https://docs.djangoproject.com/en/1.7/ref/applications/#troubleshooting). The solution should be simple: force the models to be loaded *before* any Twisted service is started (`import django; django.setup()`).