Ruby

• lib/fileutils.rb (FileUtils#chown_R): Do not skip traversal even
  if user and group are both nil, to be consistent with #chown and
  other commands.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41860 b2dd03c8-39d4-4d8f-98ff-823fe69b080e