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_call.py b/Lib/test/test_call.py
index 695ab56..99554c7 100644
--- a/Lib/test/test_call.py
+++ b/Lib/test/test_call.py
@@ -1,5 +1,5 @@
 import unittest
-from test.test_support import run_unittest
+from test import test_support
 
 # The test cases here cover several paths through the function calling
 # code.  They depend on the METH_XXX flag that is used to define a C
@@ -124,7 +124,7 @@
 
 
 def test_main():
-    run_unittest(CFunctionCalls)
+    test_support.run_unittest(CFunctionCalls)
 
 
 if __name__ == "__main__":