Features:
+* "systemctl disable" on a static unit prints no message and does
+ nothing. "systemctl enable" does nothing, and gives a bad message
+ about it. Should fix both to print nice actionable messages.
+
* man: link up systemd.directives better, so that people actually know about it
* fstab: add new mount option x-systemd-after=/foobar/waldo to allow manual dependencies to other mount points