Started fixing screens to use listeners to change to another screen
Merge branch 'feature/screens' into develop

Conflicts:
	desktop/src/main/java/edu/chalmers/sankoss/desktop/SankossGame.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/AbstractScreen.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/credits/CreditsRenderer.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/credits/CreditsScreen.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/game/GameModel.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/game/GameRenderer.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/game/GameScreen.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/lobby/LobbyRenderer.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/lobby/LobbyScreen.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/mainMenu/MainMenuRenderer.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/mainMenu/MainMenuScreen.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/placement/PlacementRenderer.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/waiting/WaitingRenderer.java
	desktop/src/main/java/edu/chalmers/sankoss/desktop/mvc/waiting/WaitingScreen.java