Upgrade the version of rsyslog installed in Docker containers to the latest version available from jessie-backports repo (currently 8.23.0-2~bpo). Based off my change to the 201803 branch (#2709). This should eliminate some memory leaks and will prevent any regressions if moving from the 201803 branch to the 201811 branch.
* [docker-base] Instruct apt-get to NOT install 'recommended' or 'suggested' packages
* Modify docker-fpm-quagga, docker-snmp-sv2 and docker-sonic-vs Dockerfile templates in order to properly install .deb dependencies
* REDIS_SERVER depends on REDIS_TOOLS; ensure REDIS_TOOLS is always installed before REDIS_SERVER
- 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
