Implement Uno and related card games

[FastLizard4]

Implement the Uno card game in Beancounter.

Someone also suggested an alternative to Uno that we may want to go with instead, but I can't recall what it was called.

[wlritchi]

I suggested 4.5, a variant of my own creation with a few friends. Include that in this issue though; it's the same framework for both games. Also Crazy Eights.