[L] change physics class y-velocity-coordinate to be like all other
y-coordinates again (positive y to go down)
[M] harmonize to 1 single gameloop that switches between title, worldmap,
ingame mode and eventually leveleditor mode
[H] introduce a special mode in DrawingContext for objects that want to draw
themselfes. This could speed up rendering of tilemaps.
[L] change physics class y-velocity-coordinate to be like all other
y-coordinates again (positive y to go down)
[M] harmonize to 1 single gameloop that switches between title, worldmap,
ingame mode and eventually leveleditor mode
[H] introduce a special mode in DrawingContext for objects that want to draw
themselfes. This could speed up rendering of tilemaps.