title: Context path generated twice when using #{resource} value expression within facelet page
body: <p>I'm using the expression <code>#{resource['library:file']}</code> within a facelets page to generate an ajaxified button with an image within an RichFaces (4.2.2.Final) toolbar. </p>
  
  <pre><code>&lt;h:form&gt;
      &lt;rich:toolbar height="40px"&gt;
          &lt;rich:toolbarGroup&gt;
              &lt;a4j:commandButton value="my label" image="#{resource['icons:icon32.gif']}"/&gt;
      &lt;/rich:toolbarGroup&gt;
      &lt;/rich:toolbar&gt;
  &lt;/h:form&gt;
  </code></pre>
  
  <p>generates the following code for the a4j:commandButton where the context path is generated twice.</p>
  
  <pre><code>&lt;input type="image" alt="my label" 
      src="/com.test.my.context/com.test.my.context/faces/javax.faces.resource/icon32.gif?ln=icons" 
      value="my label" 
      onclick="RichFaces.ajax(&amp;quot;j_idt73:j_idt76&amp;quot;,event,{&amp;quot;incId&amp;quot;:&amp;quot;1&amp;quot;} );return false;" 
      name="j_idt73:j_idt76" id="j_idt73:j_idt76"&gt;
  </code></pre>
  
  <p>If I use <code>&lt;h:graphicImage library="icons" name="icon32.gif"/&gt;</code> within <code>rich:toolbarGroup</code> the generated URL is right.</p>
  
  <p>Furthermore I've include the image by css using <code>background: url(#{resource['library:file']})</code> which doesn't gives the result I've searched for, but it works!</p>
  
  <ol>
  <li>Is the expression <code>#{resource['library:file']}</code> only allowed within css files? </li>
  <li>Where is the problem within my code?</li>
  </ol>