Combine the functionality of test_support.run_unittest()
and test_support.run_classtests() into run_unittest()
and use it wherever possible.

Also don't use "from test.test_support import ...", but
"from test import test_support" in a few spots.

From SF patch #662807.
diff --git a/Lib/test/test_textwrap.py b/Lib/test/test_textwrap.py
index b1cee30..b8964dc 100644
--- a/Lib/test/test_textwrap.py
+++ b/Lib/test/test_textwrap.py
@@ -352,11 +352,7 @@
 
 
 def test_main():
-    suite = unittest.TestSuite()
-    suite.addTest(unittest.makeSuite(WrapTestCase))
-    suite.addTest(unittest.makeSuite(LongWordTestCase))
-    suite.addTest(unittest.makeSuite(IndentTestCases))
-    test_support.run_suite(suite)
+    test_support.run_unittest(WrapTestCase, LongWordTestCase, IndentTestCases)
 
 if __name__ == '__main__':
     test_main()