Add lottery frontend program module.

As the name implies, this serves as a frontend to the lottery registration assignment class. Currently it only allows configuration of parameters, running the lottery, and saving the results (or clearing previously saved results).

See Issue #803.
++.  Since this might not be used by webmins (at least in theory), displaying an error ("Failed to update mailing lists in mailman, email websupport if you care" or some such) would be the best idea.