FSM and GameState

Adds base classes for flexible finite state machines in utils/fsm/
The Game is ported to be a (still pretty basic) StateMachine that illustrates Transitions and enter and leave events. Pause the game with p and continue with c.

The Port of Game to GameState is still a bit edgy, but this is not the focus of this commit. the only thing missing in terms of functionality is the focus-loosing on resize. To beautify it, the State-dependant input handling needs to be implemented properly.

For now I am mainly interessed if this compiles and works for you and what you think of the FSM.