[Python-Dev] Add python.exe to PATH environment variable

["Martin v. Löwis"]

> FWIW, my opinion is similar to how I read Martin's - that if a suitable,
> safe patch that cleanly uninstalls can be found, it should be included, but
> disabled by default.  Personally I'd never use it.

That's my view also (less strict now; I previously would have rejected
it outright, as I didn't consider that it might be optional and off by
default).

Regards,
Martin