* Significant code refactor and fixes by Ali1234
* Metadata dump fixed to support RL images
* Bugfix to incorrect transparent colour being selected
* Configurable empty_tile for .tmx maps - specifies a tile ID for unset/empty tiles to be remapped to
* Optional struct output type for .tmx maps with width, height layer count and empty_tile
* .tmx map layers are now sorted
* Should not break compatibility, but use 0.4.x if you don't need the new features