title: KnpMenuBuilder Menu with FontAwesome icons
body: <p>I try to create a menu builder in php, to reproduce this code :</p>
  
  <pre><code>         &lt;ul class="nav nav-pills"&gt;
              &lt;li class="first"&gt;&lt;a title="Voir panier"
                  href="{{ path('cs_web_homepage') }}"&gt; &lt;i
                      class="fa fa-shopping-cart icon-large"&gt;&lt;/i&gt; Voir Panier
              &lt;/a&gt;&lt;/li&gt;
  
              {% if is_granted("IS_AUTHENTICATED_REMEMBERED") %} 
                  &lt;li&gt;&lt;a title="Mon compte"
                      href="{{ path('fos_user_profile_show') }}"&gt;&lt;i
                          class="fa fa-user icon-large"&gt;&lt;/i&gt; Mon compte
                  &lt;/a&gt;&lt;/li&gt;
                  &lt;li&gt;&lt;a title="Déconnexion"
                      href="{{ path('fos_user_security_logout') }}"&gt;&lt;i
                          class="fa fa-power-off icon-large"&gt;&lt;/i&gt; Déconnexion
                  &lt;/a&gt;&lt;/li&gt;
              {% else %}
                  &lt;li&gt;&lt;a title="Connexion"
                      href="{{ path('fos_user_security_login') }}"&gt;&lt;i
                          class="fa fa-lock icon-large"&gt;&lt;/i&gt; Connexion
                  &lt;/a&gt;&lt;/li&gt;
                  &lt;li class="last"&gt;&lt;a title="Register"
                      href="{{ path('fos_user_registration_register') }}"&gt; &lt;i
                          class="fa fa-user icon-large"&gt;&lt;/i&gt; Inscription
                  &lt;/a&gt;
                  &lt;/li&gt;
              {% endif %}
          &lt;/ul&gt;
  </code></pre>
  
  <p>So, I begin with this code :</p>
  
  <pre><code>public function mainMenu(FactoryInterface $factory, array $options)
  {
      $request = $this-&gt;container-&gt;get('request');
      $securityContext = $this-&gt;container-&gt;get('security.context');
  
      $menu = $factory-&gt;createItem('root', array(
          'childrenAttributes' =&gt; array(
              'class' =&gt; 'nav nav-pills'
          )
      ));
  
      $menu-&gt;addChild('cart', array(
          'route' =&gt; 'cultural_store_web_homepage',
          'linkAttributes' =&gt; array('title' =&gt; 'Voir Panier'),
          'labelAttributes' =&gt; array('icon' =&gt; 'icon-user')))-&gt;setLabel('Voir Panier');
  
      return $menu;
  
  }
  </code></pre>
  
  <p>But, the icon is not added.
  I also try to put :</p>
  
  <pre><code>$menu-&gt;addChild('cart', array(
          'route' =&gt; 'cs_web_homepage',
          'linkAttributes' =&gt; array('title' =&gt; 'Voir Panier')))
          -&gt;setLabel('Voir Panier')
          -&gt;addChild('icon' =&gt; array('class' =&gt; 'fa fa-shopping-cart');
  </code></pre>
  
  <p>But it doesn't work...
  I don't really understand how to use the icon child..</p>
  
  <p>Any help ?</p>
  
  <p>Thx</p>