tool/downloader.rb: Adjusting example for
Downloader.download to implementation changes in r47693.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47708 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
enc/unicode/data: New directory for downloaded Unicode data files.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47709 b2dd03c8-39d4-4d8f-98ff-823fe69b080e