Update turnkey init fence

[JedMeister]

Update init fence to run as a systemd service:

• refactor existing turnkey-init-fence init.d script to a "normal" bash script & move to /usr/lib/inithooks/bin
• minor update for /etc/default/turnkey-init-fence:
  • use arrays rather than space separated strings
  • remove webshell port (12320) and add Adminer port (12322)
• add turnkey-init-fence.service file

Note: requires more testing...