* lib/fileutils.rb (rm_r): use lchown(2), not chown(2). [ruby-dev:26226]

* lib/fileutils.rb (cd): remove :noop option. (FEATURE CHANGE)
* lib/fileutils.rb (cp_r): should copy symlink as symlink, for also tree root. (FEATURE CHANGE)
* lib/fileutils.rb (cp_r): new option :dereference_root.
* lib/fileutils.rb: new method remove_entry.
* lib/fileutils.rb: new method remove_entry_secure.
* lib/fileutils.rb: add documentation.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@8525 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Author: aamine