Added working example of registering to GCM services (with static
GCM_Sender_Id).
Made changes needed to save the GCM device registrationId to the
GamesPlatform database via the CreateSession API call.
Refactored the GCM push notification message receiving, as now the
GCMIntentService is moved to the GamesPlatformSDK core packages.
Added a GamesPlatform GCM manager class for error handling and easier
integration.
Added a separate call for storing the Push notification Token via the
GamesPlatformAPI service in our data storage.
Push Notifications small fix.
Fixed classpath to be a relative path.
Fixed bug for Store Push Notification Token request (separate API call).
Push Notifications: added feature to show a new PN alert dialog when the
GamesPlatformSDKActivity is in the foreground.
Merge branch 'pushnotifications'