REFACTORING: moved GService code in ad-ohc class hierarchy
FIX: regressio after refactoring
REFACTORING: removed deprecated code
REFACTORING: extracted ADSHelper and AndroidHelpers classes from MainActivity
REFACTORING: AccelerometerHelpers and new package
REFACTORING: packages organization
FIX: github backgammon mobile URL
FIX: NullPointerException onScoreSubmission with no network
REFACTORING: removed duplicated code
FIX: regression - auto reject invitation when playing a game
OPTIMIZATION: single secureRandom instance
FIX: REGRESSION - invitation from notification area
CLEANUP
FIX: use local propertiy to save purchase status
Merge branch 'gservice_refactoring'
FIX: updated desktop version to new refactoring
RELEASE: v2.4
FIX: regression from in-app billing FIX - new PrivateDateManager property
FIX: removed old ADS SDKs (no more Google compliant)
RELEASE: v2.4.1