Cygport: How can I ignore duplicated files in packages

[Hamish McIntyre-Bhatty]

Hi there,

Today I'm attempting to update my python-imaging package, but I'm now 
finding that cygport has made the warning about duplicated files an error.

The source is at: https://gitlab.com/hamishmb/cygwin-python-imaging

Files are duplicated in these packages because there are .py files for 
each python release in /usr/lib/python3.*.

This doesn't seem to actually break package creation, but I'd like to 
get this reproducing correctly in scallywag, which I think will flag as 
failed because of this error.

I'm not sure whether this indicates that I'm packaging things the wrong 
way. If so, I'd be happy to learn how to improve my packages.

Hamish