should be deprecated, but I need a Shift-JIS encoded XML file to test
  against, first.
* Added support for maintaining external entity occurances in DTDs
* Deprecated the use of Document::DECLARATION.  The new default declaration
  can be gotten with XMLDecl::default()
* Refactored the encoding support code.  It should be more robust now,
  and fixes a few bugs.
* The XPath string() function now deals with Element nodes properly.
* Serialization with Output objects now works as would be expected.
* Various code cleanups, some reducing the number of warnings that Ruby 1.8.x
  produces with REXML.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@5144 b2dd03c8-39d4-4d8f-98ff-823fe69b080e