* lib/test/unit/ui/testrunnermediator.rb: moved the run flag to a more
central location.
* lib/test/unit.rb: ditto.
* lib/test/unit.rb: extracted the running code in to AutoRunner.
* lib/test/unit/autorunner.rb: added.
* lib/test/unit/collector/objectspace.rb: extracted common test
collection functionality in to a module.
* lib/test/unit/collector.rb: ditto; added.
* test/testunit/collector/test_objectspace.rb: ditto.
* lib/test/unit/collector/dir.rb: added. Supports collecting tests out
of a directory structure.
* test/testunit/collector/test_dir.rb: added.
* test/runner.rb: simplified to use the new capabilities.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4720 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
