Sort Datatables content following DIN5007, variant 1 http://de.wikipedia.org/wiki/Alphabetische_Sortierung

datatables_sort_din5007_variant1.js

// By default Datatables uses the sType 'html' for its cells and sorting.
// Therefore the sort mechanism for this sType is overwritten here as seen here:
// http://datatables.net/development/sorting#type_based

din5007Relacement = function(x) {
  x = x.replace("ä", "a");
  x = x.replace("ö", "o");
  x = x.replace("ü", "u");
  x = x.replace("ß", "ss");
  return x;
}

$.fn.dataTableExt.oSort['html-asc'] = function ( x, y ) {
  x = din5007Relacement(x);
  y = din5007Relacement(y);
  return ((x < y) ? -1 : ((x > y) ? 1 : 0));
}

$.fn.dataTableExt.oSort['html-desc'] =  function ( x, y ) {
  x = din5007Relacement(x);
  y = din5007Relacement(y);
  return ((x < y) ? 1 : ((x > y) ? -1 : 0));
}