title: window.open loadstart not working
body: <p>When I tried following, the alert statements not fired.</p>
  
  <pre><code>var ref = $window.open('http://apache.org', '_blank', 'location=yes');
  ref.addEventListener('loadstart', function(event) { alert('start: ' + event.url); });
  ref.addEventListener('loadstop', function(event) { alert('stop: ' + event.url); });
  ref.addEventListener('loaderror', function(event) { alert('error: ' + event.message); });
                          ref.addEventListener('exit', function(event) { alert(event.type); });
  </code></pre>