title: Ember.observer run on init
body: <p>I'm attempting to build an Ember app without prototype extensions and the Ember docs give examples of how to do this, but they don't include the example of when I want my observer to run on init. 
  So currently if my code were written like this:</p>
  
  <pre><code>fullNameChanged: function() {
     // deal with the change
  }.observes('fullName').on('init')
  </code></pre>
  
  <p>The only example I can find to write it is like this:</p>
  
  <pre><code>Person.reopen({
    fullNameChanged: Ember.observer('fullName', function() {
      // deal with the change
    })
  });
  </code></pre>
  
  <p>So how would I tell this code to run on init?</p>