Using Google Cloud Messaging with SimplePush

the GCM_NOTES.md file describes the actions required to acquire a GCM project ID and registration ID. In short:

1. go to https://console.developers.google.com/project
2. create a new Project (it is recommended to create several, one for:
   • Production Load
   • Development
   • Load Testing
   • Cross Product Integration
3. go to "APIs & Auth"
4. Activate "Google Cloud Messaging for Android" under "APIs"
5. create a new key under "Credentials" "Public API access.
   Optionally, you may wish to limit the IPs to include only the SimplePush servers. This will limit who can send messages using these keys.
6. Add the API Key as gcm.api_key