Build GDC on Windows

[Daniel Green]

I forgot to mention the extra files needed to finish installation, 
because I really wouldn't recommend copying the files from your MinGW 
install.
Copied from http://www.tdragon.net/recentgcc/

All files can be found at http://sourceforge.net/projects/mingw/files/

  * binutils : binutils-2.19.1-mingw32-bin.tar.gz
  * mingw-runtime : mingwrt-3.16-mingw32-dev.tar.gz & 
mingwrt-3.16-mingw32-dll.tar.gz
  * w32api : w32api-3.13-mingw32-dev.tar.gz

Optional:
  * mingw-utils : mingw-utils-0.4-1-mingw32-bin.tar.lzma
  * mingw32-make : make-3.81-20090914-mingw32-bin.tar.gz
  * gdb. http://gdcwin.sourceforge.net/ has one, but I think there was a 
newer 6.8 out there.