Log Message:
Update to 0.42

Upstream changes:
2013/11/07 (0.42)
    * add empty_element_tag_end option. thanks to Songmu
      https://github.com/kawanet/XML-TreePP/pull/2
    * ensure unicode transmitted proprely. thanks to xenoterracide
      https://github.com/kawanet/XML-TreePP/pull/1
    * it requires LWP 5.811 or later to use add_content_utf8 method in HTTP::Message
    * source repository is now on github
      https://github.com/kawanet/XML-TreePP