-Added the 'note type to assertion/lookup definitions
-Added note-related handlers to deal.lisp
-Added clause to play/move that unsets a notes' :attached-to if it's moved
-Added ping handler. It doesn't modify the table at all, just broadcasts an x/y/z coord that the front-end can use to highlight a point on the board
-Added new messages to the events list/chat message dispatch stack. Still really, REALLY need to clarify and unify those