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
from query import *
from subqueries import *
from where import AND, OR
from datastructures import EmptyResultSet
__all__ = ['Query', 'AND', 'OR', 'EmptyResultSet']