Make checkIsMyInvitation use Django to parse the URL
Using django is more reliable and makes the code easier to read as
there is no knowledge of the url layout required.
Patch by: Sverre Rabbelier
"""
Field-like classes that aren't really fields. It's easier to use objects that
have the same attributes as fields sometimes (avoids a lot of special casing).
"""
from django.db.models import fields
class OrderWrt(fields.IntegerField):
"""
A proxy for the _order database field that is used when
Meta.order_with_respect_to is specified.
"""
name = '_order'
attname = '_order'
column = '_order'