title: mm-is-menu class isn't being added, submenu doesn't work MMENU
body: <p>I have worked with mmenu many many times before and NEVER had an issue with this great plugin.
  But on new version (3.3.2) I have started facing problems.</p>
  
  <p>The mobile menu works (it slides from left etc) but mm-is-menu css class is not being added by the javascript, as result I don't get any css, submenus aren't working either. </p>
  
  <p>Environment:
  - Working on Wordpress 3.6.1 version + Foundation 3
  - JQuery 1.10.2
  - I have no errors on console. No jquery duplicates, no problems on that side.</p>
  
  <p>Structure</p>
  
  <pre><code>&lt;html&gt;
  &lt;body&gt;
     &lt;header&gt;
         &lt;a href="#mobile"&gt;Trigger&lt;/a&gt;
     &lt;/header&gt;
     &lt;div&gt;
            //Content
     &lt;/div&gt;
   &lt;footer&gt;
   &lt;/footer&gt;
      &lt;nav id="mobile" class="navigation-main" role="navigation"&gt;
        &lt;?php wp_nav_menu( array( 'theme_location' =&gt; 'primary' ) ); ?&gt;
      &lt;/nav&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>JS FILE</p>
  
  <pre><code>$(function(){
     $("#mobile").mmenu();
  });
  </code></pre>
  
  <p>The navigation structure made by WP is the same the plugin requires, and it works with previous versions of it with the same wp_nav_menu structure.</p>
  
  <p>I have been reading all the plugin documentation and everything I have is correct. I don't know what changed on the last version, maybe I'm missing something.</p>
  
  <p>Thanks.</p>