install JOC Cockpit daemon with systemd service file

Current Situation

• If the installer has root permissions then ...
  • a JOC Cockpit daemon on Linux is installed with the startscript /etc/init.d/joc
    which is a copy of $JOC_HOME/jetty/bin/jetty.sh.
  • automatically start-up is configured with chkconfig or update-rc.d (depends on the distribution).
• If the installer is started with option -u (without root permission) then ...
  • the start script will not be copied
  • a JOC Cockpit daemon can be installed manually with

    sudo $JOC_HOME/install/install_jetty_service.sh

Desired Behavior

• If the installer has root permissions then ...
  • a JOC Cockpit daemon on Linux should installed with a systemd service file /usr/lib/systemd/system/joc.service
    which is a copy of $JOC_HOME/install/joc.service.
  • automatically start-up is configured with systemctl.
• If the installer is started with option -u (without root permission) then ...
  • the systemd service file will not be copied
  • a JOC Cockpit daemon can be installed manually with

    sudo $JOC_HOME/install/install_jetty_service.sh

• Note:
  The systemd service file /usr/lib/systemd/system/joc.service will be overwritten on JOC Cockpit upgrades.
  Copy the file to /etc/systemd/system/joc.service to make needed changes.