* lib/fileutils.rb (cp_r): default is :dereference_root=>true for backward compatibility. [ruby-dev:27145]
* test/fileutils/test_fileutils.rb (test_cp_r): test it.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@9221 b2dd03c8-39d4-4d8f-98ff-823fe69b080e