+* "systemctl disable" of a unit instance removes all symlinks, should
+ only remove the instance symlink (systemctl disable of a template
+ unit however should remove them all).
+
+* journald: optionally, log debug messages to /run but everything else to /var
+
+* journald: optionally, when messages with a high log priority are logged, sync() immediately.
+
+* systemctl list-unit-files should list generated files (and probably with a new state "generated" for them, or so)
+
+* do we really need both hasprefix() and startswith()?
+