title: CakePHP customize flash message
body: <p>Normally, the <code>$this-&gt;Session-&gt;setFlash(__('My message.'));</code></p>
  
  <p>Will output:</p>
  
  <pre><code>&lt;div id="flashMessage" class="message"&gt;
      My message.
  &lt;/div&gt;
  </code></pre>
  
  <p>How can I change that, so it'll output:</p>
  
  <pre><code>&lt;p class="notification&gt;
      My message.
  &lt;/p&gt;
  </code></pre>
  
  <p>instead?</p>