Start adding a SpriteGrid class which will support loading from TMX files
Start implementing the SpriteGrid, currently the tiles are flipped vertically and only renders a single chunk...
Fix a slight issue with the Y-positioning of tiles (they're still upside down though)
Flip everything the right way around, now just need to position chunks correctly
Implement the SpriteGrid class which can load layers from TMX (Tiled) map files