Environ handling broken on Cygwin RE: Cygwin: environ problem

["Andrej Borsenkow" <Andrej.Borsenkow@xxxxxxxxxxxxxx>]

>
> There is unfortunately one more problem.

And one more. Cygwin maintains "shadow" Win32 environment, that deals
with Unix<->Win32 name conversion. Now I understand, why calling gvim
(win32 version) out of Zsh never worked - it never got correct filename.

That means, that irrespectively of dynamic loading current environment
handling is broken on Cygwin and needs rewrite.

As I understand, the sole requirement of current code is to be able to
unset environment variable. Cygwin provides unsetenv() function. So, we
could retain current code on Unix and use native Cygwin function there.

Any suggestions before I start hacking? :-)

-andrej