* xpath.c: Optimized the comparison for non-element nodes
  in xmlXPathCmpNodesExt(); the comparison is used for sorting
  of node-sets. This enhancement is related to bug #165547.
  There are other places where the old comparison function
  xmlXPathCmpNodes() is still called, but I currently don't
  know exactly what those calls are for; thus if they can be
  substituted (if it makes sense) for the new function.