Added wall and tank collision.
Merge branch 'master' of https://github.com/danielsuter/tank-wars

Conflicts:
	src/main/java/ch/tankwars/transport/game/GameCommunicator.java
	src/main/java/ch/tankwars/transport/game/GameController.java
Merge branch 'master' of https://github.com/danielsuter/tank-wars