* 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