Features:
+* define a message ID for "overmounting non-empty directory".
+
+* use polkit "imply" for binding hostname actions together
+
+* journal: when waiting for journal additions always sleep at least 1s or so, in order to minimize wakeups
+
* man page for catalog APIs
+* add catalog api for querying the raw template rather then replaced text
+
* When shutdown.target is queued begin with an asynchronous sync()?
* Add ConditionBatteryPower= or ConditionACPower=? (but definitely not both)