Add hard-coded GroupApplication and OrgApplication Models.
These are being hard-coded because the "real" Question/Answer/Quiz/Response
implementation will not be ready any time soon.
Patch by: Todd Larsen
Review by: to-be-reviewed
Mailing list EmailProperty should be StringProperty instead, so that it is
possible, for example, to supply a Google Group URL for sign-up purposes.
Patch by: Todd Larsen
Review by: to-be-reviewed