- added different models (see README.txt of the files)
- added methods to the SeaSynchronizer class to represent different ships sizes with different models
- added the client-side validation in the EditorState class
- added the server-side validation in the WaitState and ServerGameLogic class
- added Getter in the ShipMapDTO
- added the 'map.invalid' in the properties
- ShipMapTest: notify ItemRemovedEvent when calling the remove method.
- ClientGame1Player1 and ClientGame2Player2Test: Ensure opponent's is retrieved in game over state.