Rhel/CentOS 7

`build_packages rpm` now builds two rpms: `*.el6.noarch.rpm` and `*.el7.noarch.rpm`. And the new .el7 rpm uses systemd.
Also, according to the systemd docs: 

> Programs should instead perform cleanup and kill themselves with the same signal instead. See [Proper handling of SIGINT/SIGQUIT — How to be a proper program](http://www.cons.org/cracauer/sigint.html).