now actually adds usable name for systemd when service only has init
script
Merge pull request #455 from bcoca/service_systemd_initscript_fix2

now actually adds usable name for systemd when using init scripts
vastly simplified systemd detection, made enable/disable errors clearer
both of which allows us to remove 'service name detection' as if systemd
is init we still use it to handle initscripts.