Add groupid to tab header for easy hiding/showing with js

Added group id to nav-tab li elements for easy hiding/showing over js.
Now following code can be used to hide/show tab pages:
  t = document.id('tab-group52');  if (t !== null) t.style.display= 'none';
  t = document.id('tab-group52');  if (t !== null) t.style.display= 'block';