Added a card image for top card of the pile. As well, the CardImage class now automatically configures itself to use its own image as the button image. Several CardImage's methods have become static methods, as well it is now possible to generate a blank card by passing in an card when either the rank or suit is not defined (None)
Fixed a bizzare bug where the Client would receive the pile list from the server in reverse order, causing the first card in the pile to be improperly displayed