Log Message:
Update to 5.1

Upstream changes:
Release 5.1

   Fix entities in attributes only working for root node. RT #89402

Thu Oct 03 2013 Jeff Fearn <Jeff.Fearn@gmail.com>
   Release 5.0

   Add support for using XML Catalogs. (related to RT #87010)
   Add support for expanding entities.
   perl tidy FTW
   Remove xt/ deps from Build.PL. RT #78039
   Doc typo fixes. RT #66404
   Error out if args to new are not in a hash. RT #70654
   Add logic to keep entities in attributes when NoExpand is set. RT #88973

Jul 17 2013  Jeff Fearn <Jeff.Fearn@gmail.com>
   Release 4.3

   Hard code VERSION in TreeBuilder.pm for PAUSE. RT #86964

Jul 15 2013  Jeff Fearn <Jeff.Fearn@gmail.com>
   Release 4.2

   Added store_cdata to handle CDATA.
   More test coverage.