Update Pod-Simple to CPAN version 3.17

Update Pod-Simple to CPAN version 3.17

  [DELTA]

  2011-07-09   David E. Wheeler <david@justatheory.org>
  * Release 3.17

  Documented tertiary methods. Patch from Shawn H Corey.

  Added "backlink" option to Pod::Simple::XHTML. Thanks to Marc
  Green/Google Summer of Code for the pull request.

  Typos fixed in Pod::Simple::HTMLBatch. Reported by Shawn H Corey.

  Fixed quoting of value returned by a "strip_verbatim_indent()"
  code reference so that regex meta characters are properly escaped.

  Added "anchor_items" option to Pod::Simple::XHMTL. This allows
  text items (which are output as <dt> elements) to have IDs that
  can be referenced in the "#" part of a URL. Marc Green/Google
  Summer of Code.

  Added "recurse" option to Pod::Simple::Search. It's enabled by
  default; disable it to turn off recursion into subdirectories.
  Marc Green/Google Summer of Code.

  Added documentation to clarify the behavior of the "content_seen"
  method. Thanks to Olaf Alders for the pull request.