#### Why I did it
The GPG key used for Jessie's official repos has since expired, which means building 201911 images no longer works.
#### How I did it
Fake the time to be before the expiry date.
- Consolidate config.sh and start.sh scripts into one script (start.sh)
- Solve issue #435 - All dockers now run supervisord as their ENTRYPOINT
- All stdout/stderr output from processes managed by supervisord is now sent to syslog instead of their own files
- Supervisord log messages are now also sent to syslog
- Removed unused smartmontools package from docker-platform-monitor
