Add import_function method to test.test_support, and modify a number of

tests that expect to be skipped if imports fail or functions don't
exist to use import_function and import_module.  The ultimate goal is
to change regrtest to not skip automatically on ImportError.  Checking
in now to make sure the buldbots don't show any errors on platforms
I can't direct test on.

Lib/test/test_aepack.py

@@ -1,11 +1,12 @@
 # Copyright (C) 2003 Python Software Foundation
 
 import unittest
-import aepack
-import aetypes
 import os
 from test import test_support
 
+aetypes = test_support.import_module('aetypes')
+aepack = test_support.import_module('aepack')
+
 class TestAepack(unittest.TestCase):
     OBJECTS = [
         aetypes.Enum('enum'),