title: JSF readonly inputText issue
body: <p>Readonly inputText doesn't validate if <code>required="true"</code> is set.</p>
  
  <pre><code>&lt;h:panelGrid columns="3" id="townShipPanelGroup"&gt;
      &lt;p:inputText value="#{AddNewLifeProposalActionBean.beneficiariesInfoDTO.residentAddress.township == null ? '' : AddNewLifeProposalActionBean.beneficiariesInfoDTO.residentAddress.township.name}" 
          style="width:250px;margin-left:-4px;" id="townShip" readonly="true"&gt;
              &lt;f:validateLength maximum="36"/&gt;
      &lt;/p:inputText&gt;
      &lt;p:commandLink immediate="true" oncomplete="selectTownShipDialog.show()" id="selectTownShipDialogLink" action="#{AddNewLifeProposalActionBean.loadTownshipList()}"&gt;  
      &lt;h:graphicImage url="/images/search.png" style="height:30px;width:30px"/&gt;
      &lt;/p:commandLink&gt;
  &lt;/h:panelGrid&gt;
  </code></pre>