[world] Start making Tileset for new tiles
[shell] throw, not crash, if selected room isn't in a document
[shell] Create new room in its own document, instead of raw in a file.
[shell] Fix tile selector behavior
[shell] Fix tilemap-relative positions
[world] Add a new room with new tileset
[core] Don't frameskip without limit_fps
[core] Change limit_fps flag into benchmark flag
[core] Disable vsync during benchmarking
[ent world] Add files for Patroller
[ent shell world] Implement patroller movement pattern