title: PrimeFaces icons not render on the commandButton
body: <p>I am trying to use a font awesome icons with JSF+PrimeFaces. 
  I added to my pom.xml file webjars dependency:</p>
  
  <pre><code> &lt;groupId&gt;org.webjars&lt;/groupId&gt;
   &lt;artifactId&gt;font-awesome&lt;/artifactId&gt;
  </code></pre>
  
  <p>Also I have my custom css file:</p>
  
  <pre><code>body{
      background-image: url("#{resource['images/loginBackground.jpg']}");
      background-size: 100%;
      font-family: 'Belleza', sans-serif;
      font-size: 16px;
  }
  </code></pre>
  
  <p>I added css's resources to my page (.xhtml) in this way:</p>
  
  <pre><code>  &lt;h:outputStylesheet library="css" name="login.css"/&gt;
      &lt;h:outputStylesheet library="webjars" name="font-awesome/4.3.0/css/font-awesome-jsf.css"/&gt;
  </code></pre>
  
  <p>But unfortunately when I set icon css class in commandButton component:</p>
  
  <pre><code>&lt;p:commandButton icon="fa fa-sign-in" id="submit" value="Login" ajax="false"/&gt;
  </code></pre>
  
  <p>The icon is not display on my button.</p>
  
  <p>My others settings (<strong>web.xml</strong>):</p>
  
  <pre><code>  &lt;context-param&gt;
          &lt;param-name&gt;primefaces.THEME&lt;/param-name&gt;
          &lt;param-value&gt;none&lt;/param-value&gt;
      &lt;/context-param&gt;
  
      &lt;servlet&gt;
          &lt;servlet-name&gt;Faces Servlet&lt;/servlet-name&gt;
          &lt;servlet-class&gt;javax.faces.webapp.FacesServlet&lt;/servlet-class&gt;
          &lt;load-on-startup&gt;1&lt;/load-on-startup&gt;
      &lt;/servlet&gt;
  
      &lt;!-- MAPPING SECTION --&gt;
      &lt;servlet-mapping&gt;
          &lt;servlet-name&gt;Faces Servlet&lt;/servlet-name&gt;
          &lt;url-pattern&gt;*.xhtml&lt;/url-pattern&gt;
      &lt;/servlet-mapping&gt;
  </code></pre>
  
  <p><strong>Libraries versions:</strong></p>
  
  <ul>
  <li>JSF 2.2</li>
  <li>PrimeFaces 5.1</li>
  <li>Font-Awesome 4.3.0-1</li>
  </ul>