Avoid duplicate white cards

This is the right idea, but it's difficult to test the invariants because
the discards aren't tracked.
Use Autobahn as a Resource; closes #41

This runs Autobahn as a Resource under TwistedWeb, instead of as a
separate Twisted Service, which allows all communication to happen over
good ol' Port 80, thus avoiding portblocking by most firewalls.

Cherry-picked off the OpenShift deployment work.
Yeah, that's right.
Merge branch 'topic/wsresource'
Merged in white card uniqification
Added a push div to hand to fix display issues when you have 0 cards
Added some white cards