restore requestAnimationFrame polyfill for older browsers that do support WebGL
Tile class work
Test some interactions between the Scene object and the Tile object
Pass the TileSource to the Tile object
Move over zoom calculation to tile source
Issue with Object.assign overriding values on Tile Object
Remove method
Fix tests
Fix broken leaftlet tests, move TileSource construction to create method
Back off some tests
Fix rebase
Fix tests
Add worker test back