parents.

* Makefile.in, win32/Makefile.sub (distclean-rdoc): added to remove
  temprary rdoc.

* Makefile.in, win32/Makefile.sub (distclean): removes extout
  directory.

* Makefile.in, win32/Makefile.sub (clean-ext): skips non-existent
  directories.

* common.mk (clean, distclean): cleans rdoc.

* configure.in (RMDIRS, RMALL): added to clean extout.

* lib/fileutils.rb (FileUtils#rmdir): added :parents option.

* lib/mkmf.rb (create_makefile): cleans installed files at clean
  instead of distclean.

* lib/mkmf.rb (create_makefile): added clean-so and clean-rb.

* lib/mkmf.rb (def init_mkmf): added DISTCLEANDIRS.

* lib/un.rb (rmdir): added -p option.

* tool/rmdirs, win32/rmdirs.bat: removes directory and the parents.

* win32/rm.bat: added -r option.


git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@21764 b2dd03c8-39d4-4d8f-98ff-823fe69b080e