title: Ember.js: Observing all object properties
body: <p>I would like to observe all changes on an object properties.<br>
  In the following example, i would like to be notified by the personChanged observer if firstname or lastname is changed.<br>
  BUT I would like to have something generic applied on all object properties (using Ember.keys() ??)
  How to replace 'firstname', 'lastname' with something more generic ?</p>
  
  <p>In my example:</p>
  
  <p><code>personChanged</code> is called when <code>firstname</code> or <code>lastname</code> is changed:</p>
  
  <pre><code> App.MyObject: Ember.Object.create({
     firstname: 'first',
     lastname: 'last',
     personChanged: Ember.observer(function() {
              console.log("person changed");
     }, 'firstname', 'lastname') 
   })
  </code></pre>