* ext/date/lib/date/format.rb: removed empty file by @vipulnsward.
* ext/date/lib/date.rb: removed needless require.
  [fix GH-647]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46633 b2dd03c8-39d4-4d8f-98ff-823fe69b080e