Also improve KILLPIDS tracking.
Waiting on multiple jobs and relying on wait exit code being != 0 if at
least one process returned != 0 might not be portable but is the best we
can do for now. We can address that in the future.
Some values we export in cn=monitor are not managed in a single place,
instead, a task exists that gathers a snapshot of the lloadd state and
stores it for monitor consumption. This exposes a race between the test
reading it out and lloadd updating this cached copy. While we still have
to rely on a shell, rather than being intelligent about whether or not
we should emit a readout into search.out or wait and try again (which is
what test004-monitor does), just filter this attribute out.
