title: set->Flash not working when called from Jquery
body: <p>I'm working on a CakePHP project, on a view I'm calling a method in the controller like this:</p>
  
  <pre><code>var addEnv = "&lt;?php echo $this-&gt;Html-&gt;url(array('action' =&gt; 'controller_method')) ?&gt;";
  $.post( addEnv, function(  ) {
       location.reload();
  });
  </code></pre>
  
  <p>The controller method looks like this:</p>
  
  <pre><code> public function controller_method()
      {
         if($this-&gt;request-&gt;is('post'))
         {   
              $this-&gt;someTable-&gt;set(array(
              'comments' =&gt; "PUM"
            ));
            $this-&gt;someTable-&gt;save();
            $this-&gt;Session-&gt;setFlash(__('DATA SAVED SUCCESSFULLY', true), 'alert-success');
            return $this-&gt;redirect(array('action' =&gt; 'edit'));
         }
     }
  </code></pre>
  
  <p>The method works correctly and I'm redirected to the edit view, which is the behavior that I expect, but the message with DATA SAVED SUCCESSFULLY text is not displayed, the same setFlash method was used on another views successfully.</p>
  
  <p>Why I cannot see the message on the view?</p>