Fix for issue8446:

Fix for issue8446:

* Don't import 'ic' in webbrowser, that module is no longer used
* Remove 'MacOS' from the list of modules that should emit a Py3kWarning on import.
  This is needed because one of the earlier tests triggers and import of this
  extension, and that causes a failure in test_py3kwarn (running test_py3kwarn
  separately worked fine)

With these changes 'make tests' no longer says that test_py3kwarn fails.