Added PlatformControllerLogic for the player and fixed a rendering bug.

The PlatformControllerLogic simply moves a player left and right and will accelerate him upwards
when he presses the jump key.  Moved rendering into a different method in both Client and
Platformer.  There was also a rendering bug at small units: since TextureRenderingLogic casts the
double data to an int before rendering, and the camera is zoomed in dramatically, this makes the
ball look as if it's moving on a grid.  Fixed this by using bigger units.