title: How can I stop or unregister the GCMIntentService service?
body: <p>I am using the GCMIntentService for receiving GCM messages. It all works as expected, but I allow the user to "quit" or stop the application, after which no new messages should be delivered to the device.</p>
  
  <p>The question is, how can I stop the GCMIntentService from running? Because after I close everything down and call "finish" on my Activity, the GCMIntentService is still getting messages which sort of causes a NullRef. </p>
  
  <p>And sure, I can do an if-statement to avoid the nullRef, but I want to stop the GCMIntentService altogether so its not longer running.</p>
  
  <p>How can I do that?</p>