Patch #555929: Cygwin AH_BOTTOM cleanup patch (*** version 2 ***)

This patch complies with the following request found
near the top of configure.in:

# This is for stuff that absolutely must end up in pyconfig.h.
# Please use pyport.h instead, if possible.

I tested this patch under Cygwin, Win32, and Red
Hat Linux. Python built and ran successfully on
each of these platforms.