title: Add an extra class to the Source value of Rich Text Editor
body: <p>I have an ExtJS RichText (CQ5 Component that has been extended from the <code>CQ.form.rte</code>).  </p>
  
  <p>There are rtePlugins that are supported using the following, as anyone would:<br>
  </p>
  
  <pre><code>credit = new CQ.form.RichText({
      height       : 100,
      width        : 400,
      fieldLabel   : 'Photo Credit',
      rtePlugins   : {
          misctools: {
              features: ['specialchars', 'sourceedit'],
              specialCharsConfig: {
                  chars: CN.Author.Util.specialCharacters
              }
          }
      }
  });
  </code></pre>
  
  <p>When I click on Source Edit, I want to manipulate the DOM and add a <code>class</code> to the HTML. What I mean is, I want the RTE editor to <strong>automatically</strong> add an extra class to the Source - the value of the RTE field, before saving. Kindly help</p>