Fix: Length menu language with wrapper element wasn't correctly populated

* Due to the manipulation of DOM elements rather than strings for the
  length list, the browser was cropping elements which were being cut
  short. Fix is to switch back to string manipulation, which can be done
  easily using the outerHTML property of the DOM element. This is
  supported in all browsers since Firefox 11, so happy to use it here.
* See thread 21170 for more information