git repositories for cygwin packaging - please test

[Jon Turney]

On 04/08/2019 21:08, Jon Turney wrote:
> Since it's intended that these repositories will only contain cygport 
> scripts, patches, and other packaging files, and to prevent the 
> accidental committing of upstream archives, pushes containing large 
> binary files will be rejected.

Actually, it seems that I'd configured things so that pushes containing 
binary files larger than 1kB were being rejected.

This was catching some repos which contain icon(s) (for a menu item), so 
I've adjusted rule to permit those (based on file extension).