inverted the else if statement in ServerGameLogic.java received() so that
if the map check returns that the map is correct the programm continues on
instead of throwing an error message and removed the hard limit of an 10x10 map in the checkMap() Method
edited in BattleState.java the receivedMsg() method so that if the game moves to the game over state
the remaining opponent ships will be added to the list of the opponenets instead of your own list.
edited the ShipMap.java so that when the notifylisteners is called for removing an object it will be
handled as an ItemRemovedEvent instead of an ItemAddedEvent
