* NEWS: Add that Fixnums and Bignums are frozen

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39340 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-02-21

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39341 b2dd03c8-39d4-4d8f-98ff-823fe69b080e