Added logic for tile rotations and updated support for new tiled version

With this release I added support for tile rotations, or tiles which are being flipped. I know, the terms are a bit confusion but when I speak of tile rotations I actually mean if a tile is being flipped horizontally, vertically or diagonally. Aside of that no new logic has been introduced. Why I decided to do a major release is because of the new Tiled version 1.5.0 which has been released not long ago.