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
Third-party code that is *not* part of the application image (the Google App
Engine SDK in trunk/thirdparty/google_appengine, for example) belongs in
trunk/thirdparty. For third-party code that *is* part of the application
image, see the notes in trunk/app/README.
== THIRD PARTY LICENSES ==
Third-party code must also include a license text file, named LICENSE or
COPYING, in the package subdirectory. If the third-party package subdirectory
is maintained automatically with a tool such as svn_load_dirs.pl (which
removes files, such as license text files, that were added later to the
"target" directory), place the license text file in the trunk/app directory
and add the package name as a suffix.