fix test_py3kwarns
The fact that this was failing and went unnoticed so long seems like a good argument for being able to enable and disble py3kwarnings through Python.
diff --git a/Lib/plat-mac/macostools.py b/Lib/plat-mac/macostools.py
index 643ba67..d7724fa 100644
--- a/Lib/plat-mac/macostools.py
+++ b/Lib/plat-mac/macostools.py
@@ -5,7 +5,7 @@
"""
from warnings import warnpy3k
-warnpy3k("In 3.x, the macostools module is removed.")
+warnpy3k("In 3.x, the macostools module is removed.", stacklevel=2)
from Carbon import Res
from Carbon import File, Files