Refactored the MongoDb PokerDemo application, centralizing the collection names of Player and Account domain classes.
Made complementing additions to the MongoDb PokerDemo data model to support transactional behavior (mainly a good-enough atomicy for the sake of this simple demo), not built in to MongoDb natively.
Redesigned the deposit algorithm in MongoDb PokerDemo, using FindAndModify to allow atomicy on a single find/write.
Fixed bug in the MongoDb PokerDemo deposit algorithm.