Revert r42938 "* lib/rubygems: Update to RubyGems 2.1.3"

It breaks build.
http://u64.rubyci.org/~chkbuild/ruby-trunk/log/20130913T200302Z.diff.html.gz

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42941 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rubygems/commands/yank_command.rb

@@ -9,7 +9,21 @@ class Gem::Commands::YankCommand < Gem::Command
   include Gem::GemcutterUtilities
 
   def description # :nodoc:
-    'Remove a specific gem version release from RubyGems.org'
+    <<-EOF
+The yank command removes a gem you pushed to a server from the server's
+index.
+
+Note that if you push a gem to rubygems.org the yank command does not
+prevent other people from downloading the gem via the download link.
+
+Once you have pushed a gem several downloads will happen automatically
+via the webhooks.  If you accidentally pushed passwords or other sensitive
+data you will need to change them immediately and yank your gem.
+
+If you are yanking a gem due to intellectual property reasons contact
+http://help.rubygems.org for permanant removal.  Be sure to mention this
+as the reason for the removal request.
+    EOF
   end
 
   def arguments # :nodoc:
@@ -21,7 +35,7 @@ class Gem::Commands::YankCommand < Gem::Command
   end
 
   def initialize
-    super 'yank', description
+    super 'yank', 'Remove a pushed gem from the index'
 
     add_version_option("remove")
     add_platform_option("remove")