Update the Linux service scripts to use systemd services instead of init.d

[RishiKumarRay]

Fixed #426

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[natechadwick]

@RishiKumarRay
I am not sure that this is the right approach. After changing these scripts, existing installs wouldn't be able to uninstall or install the existing services that are using init.d. Also these start scripts copy shell scripts that are based on init.d format. It may be cleaner to create 3 separate service instal shell scripts for systemd that handles install / uninstall of equivalent systemd service units.

https://www.digitalocean.com/community/tutorials/understanding-systemd-units-and-unit-files

The existing scripts could also be used if we added a prompt for if they want systemd or init.d - but may be easier to just have like install-jetty-service-systemd.sh as a seperate script for example.