title: How to disable addAll and removeALL button in <rich:picklist> 4.1
body: <p>I want removeAll and addAll need to be disable .
  i tried</p>
  
  <pre><code>'
   .rich-picklist-control-removeall 
   {
   display:none;
   }
  '
  </code></pre>
  
  <p>above one not working</p>
  
  <p>'
  <code>removeAllvisible="false"'</code> --- no such attribute in 4.1</p>
  
  <p>please suggest</p>