Ruby

merges r28428,r28429,r28430 and r28444 from trunk into ruby_1_9_2.¶

• test/ruby/envutil.rb (EnvUtil#invoke_ruby): get rid of possible
  deadlock.
  --
• test/ruby/envutil.rb (EnvUtil#invoke_ruby): change the
  environment of spawned process only.
  --
• test/ruby/envutil.rb (Test::Unit::Assertions#assert_in_out_err):
  return the exit status.
  --
• test/ruby/envutil.rb (EnvUtil#invoke_ruby): no needs to copy the
  original ENV, since it's done in spawn automatically.
  [ruby-dev:41733]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@28500 b2dd03c8-39d4-4d8f-98ff-823fe69b080e