refactor(tileMap): cleanup abstraction for editor use

- Put in a few refactoring notes about points to hit.
- add formats/ directory for storing tile map formats.
refactor(tileMap): remove tilemap and replace with map loader abstraction

- Still very WIP, but it does W so the IP is okay to commit
refactor(tileMap): clean up type validation errors in tilemap
refactor(tileMap): bring back objects for layers
feat(tileEditorView): support touch pan
Merge branch 'master' of github.com:justindujardin/pow-edit