Changes for "Upgrade to FB login" button to call API for the call for
adding a Facebook login to an existing HMAC login.
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.
Merge branch 'pushnotifications' into embedded_facebook

# By Doncho Popkrastev
# Via Doncho Popkrastev
* pushnotifications:
  Fixed classpath to be a relative path.
  Push Notifications small fix.
  Added a separate call for storing the Push notification Token via the GamesPlatformAPI service in our data storage.
  Added a GamesPlatform GCM manager class for error handling and easier integration.
  Refactored the GCM push notification message receiving, as now the GCMIntentService is moved to the GamesPlatformSDK core packages.
  Made changes needed to save the GCM device registrationId to the GamesPlatform database via the CreateSession API call.
  Added working example of registering to GCM services (with static GCM_Sender_Id).
  Changes for "Upgrade to FB login" button to call API for the call for adding a Facebook login to an existing HMAC login.

Conflicts:
	GamesPlatformSDK/.classpath
	GamesPlatformSDK/src/com/w3i/gamesplatformsdk/test/GamesPlatformSDKActivity.java
	GamesPlatformSDKTest/.classpath