title: Canonical Registration ID and message ID format
body: <ol>
  <li><p>I have a problem with understanding <code>Canonical Registration Id</code> and getting it returned by Google. I have deliberately registered my Android app twice (to test <code>Canonical Registration Id</code>) but when I try to push a message to both <code>Registration Ids</code> I don't get in the return from Google a <code>Canonical Registration Id</code>. </p></li>
  <li><p>In addition, I would like to know what the format of the message Id returned by Google means. I can see in the log that it seems to consist of three parts <code>&lt;something&gt;:&lt;something2&gt;%&lt;something3&gt;</code>. Any idea what they mean? Does the 3rd part identify the device?</p>
  
  <p>[INFO  com.bipper.filters.PushUpdatesFilter] [ messageId=0:1349819220154718%921c249a6e2555b5 ]
  [INFO  com.bipper.filters.PushUpdatesFilter] [ messageId=0:1349819220242456%921c249a6e2555b5 ]</p></li>
  </ol>