Floatingpoint movement

According to http://flarerpg.org/todo there is one technical milestone left for 0.19 in the engine. Replacing the map coordinates with floating point numbers instead of having scaled fixed point numbers.

So I started doing this. And there are still some unsolved issues:
 * Make the movement work again. The collision detection is not working correctly, as you can run into walls and be stuck there
 * The map rendering is jumping now one tile at a time when walking around, so you have a serious shaky cam.

The corresponding data files have been updated at 
https://github.com/stefanbeller/flare-game/tree/floatingpointmovement