Add the bulldog content type to the database if it's missing.

def _ensure_content_type():
    """ Add the bulldog content type to the database if it's missing. """
    from django.contrib.contenttypes.models import ContentType
    try:
        row = ContentType.objects.get(app_label=PERM_APP_NAME)
    except ContentType.DoesNotExist:
        row = ContentType(name=PERM_APP_NAME, app_label=PERM_APP_NAME, model=PERM_APP_NAME)
        row.save()
    return row.id