Add "StopWhenUnneeded=yes" to suspend unit file.
Change "PartOf=" to "Before=" in the suspend unit file.

That's how it done in netctl; and the previous way did not work.
Update PKGBUILD and packaging script.

- add an install file with "systemctl daemon-reload"
- change name to netctl-auto-ng for consistency
- set correct config file name (netctl-auto-ng)
Add a local packaging script/PKGBUILD.

It uses git-archive instead of pushing to GitHub and downloading a
tarball from there.