Added :

1. google-play-services library - API for GCM,
usage : import into eclipse as project and reference as library into a application
2. gcm-client - GCM client application, added to the project as library
usage : import into eclipse as project, requires google-play-services library

Setup : the gcm-client needs the google-play-services library to be added as a reference, also
the gcm-client is marked as library, and is referenced by or application.