[Distutils] bdist_winist post-install script fails on non-admin Python

[David Handy]

As I promised at the distutils Birds-Of-a-Feather session at Pycon, I 
filed a defect on sourceforge with the title above, #935091

FYI for those of you who (like me) produce a Python install package using
the distutils bdist_winst command, and you rely on a post-install script
to create shortcuts, etc. -

If the user installed Python using the non-admin option, i.e. on the 3rd
screen of the Python 2.3.3 install program, "Select Components", the user
clicked the Advanced Options button and then "Non-Admin install"...

then afterwards every time that user installs a package created with 
bdist_wininst, the post-install script will not be run.

How rare of a problem is this? I don't know, but in certain situations 
i.e. on Windows XP the user installing Python may not have admin 
privileges on that machine and may be required to do a non-admin install.

I detailed the cause and a solution in the defect report. Doesn't look
terribly hard to fix.