title: Escape html (href) in grid extjs4
body: <p>I have to escape all the HTML in my Extjs grid. 
  I used the gonfig :</p>
  
  <pre><code>return Ext.String.htmlEncode(value);
  </code></pre>
  
  <p>in the renderer of my column and it works like a charm for the simple html like <code>h1</code>, <code>b</code>, <code>i</code>, etc.</p>
  
  <p>However, if I put the following code in a cell : </p>
  
  <pre><code>&lt;a href="#" onclick="alert('Alert !!')"&gt; foo &lt;/a&gt;
  </code></pre>
  
  <p>When I click on the cell, the alert is dispatched.... </p>
  
  <p>How could I prevent it ?</p>