function _createList(doc, type) {
    return doc.createElement(type);
  }
Converts an HTML fragment/element into a unordered/ordered list

@author Christopher Blum <christopher.blum@xing.com>
@param {Element} element The element which should be turned into a list
@param {String} listType The list type in which to convert the tree (either "ul" or "ol")
@return {Element} The created list

@example
   <!-- Assume the following dom: -->
   <span id="pseudo-list">
     eminem<br>
     dr. dre
     <div>50 Cent</div>
   </span>

   <script>
     wysihtml5.dom.convertToList(document.getElementById("pseudo-list"), "ul");
   </script>

   <!-- Will result in: -->
   <ul>
     <li>eminem</li>
     <li>dr. dre</li>
     <li>50 Cent</li>
   </ul>