misc/ruby-electric.el: Minor refactoring.

* misc/ruby-electric.el (ruby-electric-insert): Check
  ruby-electric-is-last-command-char-expandable-punct-p here.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40306 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
misc/ruby-electric.el: Decrease the excess voltage of automatic matching.

* misc/ruby-electric.el (ruby-electric-closing-char): New
  interactive function bound to closing characters.  Typing one of
  those closing characters right after the matching counterpart
  cancels the effect of automatic closing.  For example, typing
  "{" followed by "}" simply makes "{}" instead of "{ } }".

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40307 b2dd03c8-39d4-4d8f-98ff-823fe69b080e