Added highscore screen and added option to show highscores to the main screen refs #44
Merge branch 'master' of https://github.com/boskoop/comet-pinball

Conflicts:
	src/game/application/src/main/java/ch/m02/comet/pinball/Pinball.java
	src/game/logic/src/main/java/ch/m02/comet/pinball/logic/internal/state/AbstractState.java