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_urllib.py b/Lib/test/test_urllib.py
index bc87b34..6afbe2f 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -408,14 +408,14 @@
 
 
 def test_main():
-    test_suite = unittest.TestSuite()
-    test_suite.addTest(unittest.makeSuite(urlopen_FileTests))
-    test_suite.addTest(unittest.makeSuite(urlretrieve_FileTests))
-    test_suite.addTest(unittest.makeSuite(QuotingTests))
-    test_suite.addTest(unittest.makeSuite(UnquotingTests))
-    test_suite.addTest(unittest.makeSuite(urlencode_Tests))
-    test_suite.addTest(unittest.makeSuite(Pathname_Tests))
-    test_support.run_suite(test_suite)
+    test_support.run_unittest(
+        urlopen_FileTests,
+        urlretrieve_FileTests,
+        QuotingTests,
+        UnquotingTests,
+        urlencode_Tests,
+        Pathname_Tests
+    )