Prevent unnecessary calls (by peinguin)
added night mode button (credits to gurshabad)
fix issue when you reach 2048 and no winning message appears (credits to UnidentifiedMan)
No more ugly color when a button was clicked (credits to GreatWizard)
Optimization for tileMatchesAvailable (credits to kingjiv)
on Galaxy SII and S, to alleviate flickering issues while moving tiles (credits to infect2)