title: Add an image or icon to primefaces tab header
body: <p>im trying to use an image /icon on a tab header instead of text title(or may using both of them), i was testing using titleStyleClass seting an image background but doesnt work</p>
  
  <p>my primefaces tab:</p>
  
  <pre><code> &lt;p:tab titleStyleClass="tCliente" title="Vehiculo"&gt;
  </code></pre>
  
  <p>My css style</p>
  
  <pre><code> .tCliente 
  
   {     
     background-image: url(../images/logo_tropidatos.gif);
   }
  </code></pre>
  
  <p>Thanks for your help :D</p>