Integrate openid directly with Frabjous

[Graham Binns]

There's already a django_openidconsumer package, which works quite well, but it would be nice to have something more extensible within Frabjous. We should take the work that django_openidconsumer does and build on it in Frabjous. Alternatively, there may be other packages that Frabjous could use as a replacement for django_openidconsumer.