ecpg -? option doesn't work in windows

ecpg option --help alternative -? doesn't work in windows.
In windows, the PG provided getopt_long function is used
for reading the provided options.

The getopt_long function returns '?' for invalid characters
also but it sets optopt option to 0 in case if the character
itself is a '?'. But this works for Linux and others, whereas
for windows, optopt is not 0. Because of this reason it is
failing.

I feel, from this commit 5b88b85c on wards, it is not working.
I feel instead of fixing the getopt_long function to reset optopt
parameter to zero whenever it is returning '?', I prefer fixing
the ecpg in handling the version and help options seperate.

Patch is attached. Any one prefers the getopt_long function
fix, I can produce the patch for the same.

Regards,
Hari Babu
Fujitsu Australia