title: Callback for change in URL in Ember v1.0.pre
body: <p>I want to call a function when their is a change in URL. 
  In newer versions of Ember, we can do this by observing <code>currentPath</code>. 
  In this version, I tried this:</p>
  
  <pre><code>Ember.Route.reopen({
    enter: function(router) {
      console.log('change in URL and need to be called once per change in URL');
    }
  });
  </code></pre>
  
  <p>Since there are nested routes, so this method was called mutiple times.</p>