Isometric / Orthogonal split. Fixed flip values.

Found this project a few days ago after not being satisfied with the default Loom TMX parser. I fixed the flip values so that you can rotate tiles in Tiled using x, y, and z and they will draw properly in Loom. I also added detection for isometric maps and fixed the x & y positioning of those tiles. No flip values for isometric maps yet, but maybe in the future. Feel free to ignore this pull request, just figured these changes might be helpful to others in the future.