Ruby

• lib/set.rb (Set#{<,>,<=,>=}): Define comparison operators as
  shorthand for the {proper_}{subset?,superset?} methods (finally).
  Given a push by Alexander E. Fischer.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36853 b2dd03c8-39d4-4d8f-98ff-823fe69b080e