[winGRASS] libtiff in cygwin

[Huidae Cho]

Hi,

I found a bug in the libtiff package distributed with cygwin and my
grass6 package doesn't work with it. For those who already installed
wingrass, just download http://geni.ath.cx/grass/cygtiff-5.dll and copy
it to c:\cygwin\usr\local\bin. I've recompiled tiff-3.7.1 and updated
the setup.ini on my site, so new users may not have any problem.

Thank you.
Huidae Cho