Features:
+* "systemctl preset-all" should probably order the unit files it
+ operates on lexicographically before starting to work, in order to
+ ensure deterministic behaviour if two unit files conflict (like DMs
+ do, for example)
+
* resolved should optionally register additional per-interface LLMNR
names, so that for the container case we can establish the same name
(maybe "host") for referencing the server, everywhere.