Tiled Map Loader 0.6

I've updated the tmx format Tiled map loader for SFML bringing it to version 0.6. Foremost I've fixed a bug where layer textures were not cleared when loading a map drawn using vertex arrays (the preferred draw method) which meant that after several map changes the amount of stored textures could get very large, and layers would often be drawn using incorrect textures. I've also added a RenderStates property to the MapLayer struct, as well as a setter for the shader property of the render states. I found this useful for times when layers were used to represent things like water or lava because it means neat distorion/reflection or other animated effects can be performed through a fragment shader. You can find the download in the usual place.