Changed lobbyWindow to extend JFrame in order for the client to give it
a window close listener that will properly disconnect from the server by
calling serverConnection.disconnect(true);
Added map of tids to observed games since user can observe multiple
games at once.
Found TableScreen was being created at the wrong location so I moved it
to the right location. Created table class and created a map of tids to
tables in the Client so client knows which table to update and which
table to observe or join.