title: Parsley.js remote validation response still validates to true after ParsleyUI.addError
body: <p>I have this form: </p>
  
  <pre><code>&lt;form method="post" id="myForm" data-parsley-validate&gt;
  &lt;input type="text" name="firstName" id="firstName" required&gt;
  &lt;input type="text" name="lastName" id="lastName" required&gt;
  &lt;input type="text" name="userName" id="userName" 
              data-parsley-trigger="focusout" 
              data-parsley-remote
              data-parsley-remote-options='{ "type": "POST" }'
              data-parsley-remote-validator='validateName'
              required&gt;
  &lt;input type="button" id="formSave" name="submit" value="Next"&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>And script: </p>
  
  <pre><code>var userName = $('#userName').parsley();
  var _xsrf = $("[name='_xsrf']").val();
  $('#myForm').parsley()
      .addAsyncValidator('validateName', function(xhr) {
          window.ParsleyUI.removeError(userName, 'name-exists');
          if (xhr.status == '404') {
              window.ParsleyUI.addError(userName, 'name-exists', "Name already exists.");
              return 404;
          } else if (xhr.status == '200') {
              return 200;
          }
      }, '/validate/?country=' + country + '&amp;_xsrf=' + _xsrf);
  </code></pre>
  
  <p>The error message is displayed correctly if user already exists, however the field is still validated as correct.  </p>
  
  <p>Doing this was so easy in v1 of Parsley.js : /</p>