Fix UI re taskConfig changes
Fix check  for Monthly last day of the month
Assume NX Jobs w/o listener are removed.

As there is a "window" currently, where this might happen.
We will probably need to revisit this, maybe GC the jobs
instead removing them directly from NexusTaskInfo.
Enforce one day to be selected in task weekly/monthly schedule
Reschedule called wrong method
Fix YUM ITs after config changes

As YUM juggles a lot with task vs config instances
(as before they were same), but after latest changes
the config _is_ a copy, and modifications to it
are NOT affecting tasks anymore, unless task excplicitly
reconfigured.
Renamed method to better reflect what it does
Task by key may return null, guard against it
Applied H2 changes recommended by Stuart

FS lock used, changed lock recovery code, and cleanup up
a mess I did when code got initially "borrowed"
Merge remote-tracking branch 'origin/master' into dirsupport-move-simplification