File Resources
Added support for Resources that are File based.
Removed Texture getTexture(String) to reduce ambiguity.
Updated BitmapFont for compliance, uses getTexture(Resource) now.
Fixed order of operations in GL.color(int).
Removed automatic invalidation of Resource on ResourceBased.unload().
Added call to Resource.invalidateAll() in WindowController.shutdown().
Added boolean renderAfterUpdate in WindowController.