Added tileset
The branch now compiles

-Tilesets are parsed and added to TextureLibrary
-Removed CustomDrawable and SlicedTexture modules
-TextureLibrary now returns a union type
-Cleaned module Render (a little), the framerate has somehow increased
-Render can now use tilesets and tiles
-TODO : Send more work to the GPU in Render
Cleaned rendering everywhere
Tiles are now rendered on GPU
Merge pull request #97 from GL-MPRI-2014/tileset

Tileset