cygport file attached.

This is a followup to Yaakov's suggestion in

   https://sourceware.org/pipermail/cygwin-apps/2020-May/040049.html

After I've uploaded this, someone should move all the minizip stuff under zlib 
on sourceware to the new minizip directory.  Or else that should be done first, 
I'm not sure which.  I guess the only question is whether calm will complain if 
it's done in the wrong order.

Ken