added empty implementation for update-method
now uses EasyGridBagLayout
copied over from GameView.java. Not yet extended in any way
fixed indent in DiceController.java
Dice are now created in constuctor, as are lockbuttons
now initializes dice-field correctly
now draws itself
DiceController now formally implements ActionListener
no longer implements Observer-interface
DiceModel now has clear()-method for clearing it's state
now knows if dice can be rolled or locked

canDiceBeLocked()-method was faulty and canDiceBeRolled() did not exist
constructor's parameters now have sane names
gave boolean-getters is-prefixed names
fixed canDiceBeLocked and simplified constructor

canDiceBeLocked now actually calls canDiceBeRolled. Constructor no
longer calls clear() (as nobody would care).
now adds itself as DiceModel's observer
added isDieLocked-method
now sets lock-buttons to correct state
added RollAction-class
added LockAction-class
attached a LockAction to each lockButton