When I'm using tace for a test load to check syntax etc., I want to exit
without committing changes. "quit" doesn't do that. ^C does. However
it leaves database/lock.wrm set. So I shouldn't be able to do any further
loading until I delete that, right? But currently I'm not seeing any lock:
subsequent tace sessions have write access without complaining.
This is some ace4_6, probably the first.
Desideratum would be a proper quit-without-saving.