runner.rb: elapsed times

* bootstraptest/runner.rb (show_progress): show each elapsed times
  in verbose mode.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46378 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
bootstraptest/test_{fork,io,thread}.rb: reduce sleep times

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46379 b2dd03c8-39d4-4d8f-98ff-823fe69b080e