title: navigation by action for p:menuitem doesn't work
body: <p>I am currently using PrimeFaces 5.</p>
  
  <p>I have this method in a bean called home:</p>
  
  <pre class="lang-java prettyprint-override"><code>public String panelSearch() {
     pnlsearch = true;
     return "home";           
  }
  </code></pre>
  
  <p><code>pnlsearch</code> is a property that makes a panel visible</p>
  
  <p><strong>home.xhtml</strong> contains:</p>
  
  <pre class="lang-xhtml prettyprint-override"><code>&lt;p:menubar&gt;
     &lt;p:menuitem id="mnusearch" 
                 value="Search"
                 ajax="true"
                 action="#{home.panelSearch}"
                 icon="ui-icon-search" /&gt;
  
       &lt;p:menuitem  value="Search"   &gt;
          &lt;p:commandLink  ajax="false"
  
                         action="#{home.panelSearch}"
                        value="Search" /&gt;
      &lt;/p:menuitem&gt;    
  &lt;/p:menubar&gt;
  
  &lt;h:panelGrid rendered="#{home.pnlsearch}"&gt;...&lt;/h:panelGrid&gt;
  </code></pre>
  
  <p><code>panelSearch</code> is called with action in both  <code>p:menuitem</code> and in <code>p:commandLink</code>
  but <code>panelSearch</code> is visible only with <code>p:commandLink</code></p>
  
  <p>Why <code>panelSearch</code> is not made visible with a click on <code>p:menuitem</code> alone as well?</p>
  
  <p>note: <code>p:commandLink</code> is called no matter the navigation-rule in faces-config.xml</p>