Multiprocessing for job submission, event handlers, poll & kill.
Fixed missing import in cat-log command.
Fix task events test.
Got submit command working.
Run mode as global flag.
Restored simulation mode.
Removed some spurious line-end chars.
Corrected a shutdown test reference log.
Tidy suite shutdown.
Fixed database test

Comparison of db events with the reference version was failing on this
branch entirely due to a difference in event ordering, possibly because
"order by name, message" is ambiguous when only a few events recorded
messages?  Default ordering works on this branch and master.