Initial commit
Fix Workbook.Saved on game win
Improve end game animation exit
Define grid storage format contants
Fix animations
Add ultimate 131072 tile
Update codebase with functional separation & interfaces

Execute calculation of all moves in memory before rendering.
Add IControls interface & KeyboardControls
Performance improvements
GameOver detection
Basic support for custom skins
Keep Workbook save state
Refactor GamesManager
Add LocalStorage
Full support for tile skins

Tiles are now valued by index (eg. 11=2048)
Game value is rendered by skin
Improved comments