Minor cleanup of various methods in CardHand and BattlefieldZoneView
Removed some minor commends
Removed code duplication by making `removeCardActive` inside `CardView`
Clearing targetable and clearing active is the same thing
`setTargetable` is now an abstract method in `CardView`
Avoiding FindBugs warning. cardId *is* initialized but findbugs doesn't
know it because it's done with reflection.
Changed package of some view classes
Corrected location of FXML documents
Starting a new game no longer starts a new connection. Can now continue
being in lobby while playing, and also after playing a game.
Avoiding NPE when a game ends