persona support is now functional

There's still a bunch of stuff that needs to be cleaned up to have it be
more correct, though.
added config optoin to make Persona audience configurable
cleaned up dead code and made changes @seansaleh suggested
removed line that tried to see if user was signing up multiple times

in my tests it seems like this doesn't even work in Orthus's current
Google OAuth implementation. If a user tries to sign up again with the
same account it just replaces the information filled out with the new
entry.

It might be a good idea to prevent multiple sign ups in the future, but
this doesn't do the job.
Merge pull request #6 from gerow/master

Added Persona Support