FEATURE: added in-app billing API
FIX: support for new PrivateDataManager
UPDATE: google-play-services v9
FIX: rtSend quota + firstroll bug
FIX: stop ping on abandon/resign received
CLEANUP: syso
CLEANUP: java warnings
UPDATE: target-sdk=android-18
RELEASE: v2.1.4
FIX: ads refactoring and first start related bug
FIX: ads show request
FIX: improved ELO rating calculation.
FIX: some nullPointerException errors
FEATURE: added new 8 achievements
FEATURE: fibs and tiga g+ leaderboards
RELEASE: v2.1.5
RELEASE: v2.1.6