Added the Main class, which contains the game loop and handles updating
and rendering.

Also added basic Sprite and Bitmap rendering. Sprites are rendered onto
Bitmaps, which are then rendered onto the screen.
This mechanism greatly simplifies things like HUDs.
Added Game class and included it into the updating and rendering process
Changed sprite rendering to make animation and rendering in gerneral
easier
Added Animation class and changed fps in Main to public static final
Merge branch 'animation'
Added Tiles, Tilemaps, Bitmaps, Image loading and Sprites.
Also completed the rendering mechanism of Sprites, Bitmaps and Tiles.
Merge branch 'master' of https://github.com/LeonardVollmann/Platformer into tile