getopt() for Windows

When looking for a C++ option parser that works on linux and windows
i found XGetopt by Hans Dietrich Software but given that it had been published in 2003 i had to make some modification to make it work on windows properly. So my version is here (in Getopt).

Simply include  #include "XGetopt.h" instead of <unistd.h>  and you have an option parser running on windows and linux.