title: Parsley custom validator is not working for javascript installation
body: <p>I have the simplest possible form with the simplest custom validator and it is not working, see <a href="http://jsfiddle.net/M55M4/" rel="nofollow">http://jsfiddle.net/M55M4/</a> What is wrong?</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;form id="myform"&gt;
      &lt;input type="text" data-parsley-myvalidator="foo" data-parsley-required /&gt;
      &lt;input type="submit" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <pre class="lang-js prettyprint-override"><code>$('#myform').parsley({
      validators: {
          myvalidator: function () {
              return {
                  validate: function (value, requirements) {
                      alert('myvalidator');
                      return false;
                  },
                  priority: 32
              }
          }
      },
      messages: {
          myvalidator: 'my validator failed'
      }
  });
  </code></pre>