git repositories for cygwin packaging - please test

[Andrew Schulman via cygwin-apps]

> While a number of maintainers keep their cygwin packaging under some 
> sort of version control, there is currently no central collection of 
> these repositories.
> 
> To remedy this lack, using the same ssh key you use for sftp package 
> upload, package maintainers can now also push to git repositories, like so:
> 
> git push cygwin@cygwin.com:/git/cygwin-packages/<packagename>
> 
> where <packagename> is a package name you are listed as a maintainer for 
> in http://cygwin.com/cygwin-pkg-maint.

Nice work, thanks. And, a big step towards an automated package build
server! Gold star! https://cygwin.com/goldstars/#Jty