2048: Clean up
InputListener: handle hardware key events

thanks @fython , but I'm not sure if it is working correctly
InputListener: Correct touch calculation

fixed: double triggered moving event in one touch
InputListener: Don't restart game while a movement

if you swipe onto the button
MainGame: Undo support

can revert to last step
AndroidManifest: Allow sdk higher than 14
InputListener: Reduce touch sensitivity
AndroidManifest: version bump
MainActivity: Menu improvement
InputListener: Sensitivity Settings
MainGame: Varity implementation

Varity is more ways to play this game, including original "2048", and upgraded "4096", and more.
InputListener: Improve sensitivity levels
Variety: Periodic Table Of Elements (First 20 elements)
MainView: Refactor to use SurfaceView
MainView: GPU Acceleration
AndroidManifest: Version Bump
InputListener: Improve sensitivity
MainActivity: Automatically save game state

save game state when activity paused, for next time to reinstance.
MainView: Revert to stock View

SurfaceView seems not compatible for old devices
AndroidManifest: Version Bump