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_shelve.py b/Lib/test/test_shelve.py
index a0274d5..8ef511e 100644
--- a/Lib/test/test_shelve.py
+++ b/Lib/test/test_shelve.py
@@ -121,15 +121,15 @@
     _in_mem = True
 
 def test_main():
-    suite = unittest.TestSuite()
-    suite.addTest(unittest.makeSuite(TestAsciiFileShelve))
-    suite.addTest(unittest.makeSuite(TestBinaryFileShelve))
-    suite.addTest(unittest.makeSuite(TestProto2FileShelve))
-    suite.addTest(unittest.makeSuite(TestAsciiMemShelve))
-    suite.addTest(unittest.makeSuite(TestBinaryMemShelve))
-    suite.addTest(unittest.makeSuite(TestProto2MemShelve))
-    suite.addTest(unittest.makeSuite(TestCase))
-    test_support.run_suite(suite)
+    test_support.run_unittest(
+        TestAsciiFileShelve,
+        TestBinaryFileShelve,
+        TestProto2FileShelve,
+        TestAsciiMemShelve,
+        TestBinaryMemShelve,
+        TestProto2MemShelve,
+        TestCase
+    )
 
 if __name__ == "__main__":
     test_main()