Change the low level internals of the xml library to reflect the following;

Change the low level internals of the xml library to reflect the following;
 * rewrite the code to always recursively walk the node tree when searching
    for a particular node. this is required for cases where a node with a
    particular name is located deeper in a node with the same name;
    for example -r /configuration/device/reference/device would fail in the
    previous verion
  * rename xmlGetElement to xmlGetNodeNum and add the possibility to request
    the nth node with this name
  * rename xmlGetNumElements to xmlGetNumNodes

The drawback is that this is approach slows down processing the files a bit,
but at least it can now find any xml node in any xml file.
Also, no more function changes are planned from now on.