* Levels and Doodad files will be written in gzip-compressed JSON format
* `boolProp compress-drawings false` to disable compression and save as
classic JSON format directly
* The game can still read uncompressed JSON files
The file size savings on some built-in assets:
* Tutorial 2.level: 2.2M -> 414K (82% smaller)
* warp-door-orange.doodad: 105K -> 17K (84% smaller)
