Update p5-XML-DT to 0.63.

Changes from previous:
----------------------
0.63  Mar 25, 2013
       - mkdtskel now uses strict/warnings

0.62  Jul 25, 2012
       - Add the -userdata option.
       - Document -userdata, -html and -recover.

0.61  Jul 25, 2012
        - Handle undef elements when parsing wrong formed XML.

0.60  Jul 25, 2012
        - Add -recover option to parse XML (not just HTML).

0.59  Jun 5, 2012
        - Fix POD encodings.

0.58  Apr 9, 2012
        - Adding missing pre-requisite (parent).

0.57  Apr 7, 2012
        - Let CDATA and PCDATA be processed in a different way.