* ext/extmk.rb: Show a message when extconf.rb raised an exception.
* ext/openssl/extconf.rb: Use exception raising instead of message
  and/or abort. We want to display error message to console _and_
  logging into mkmf.log.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@36929 b2dd03c8-39d4-4d8f-98ff-823fe69b080e