Use the dpkg --compare-versions operator lt-nl instead of lt where appropriate.
Do not force-enable default-on services on every upgrade.

Also drops the systemd-networkd, systemd-resolved and systemd-timesyncd
from the set of default services, but restarts them during an upgrade
if they were already running.
Enable systemd-networkd and companions by default.
Enable persistent journald logging by default.
Make systemd and systemd-sysv required packages.
Release to Tanglu staging.