Add support for tracking the processes associated with a job using
the hack of adding an extra group (from a per-host dedicated range).
This is basicly identical to the way the Linux and Solaris code works
except that it's a lot less gross because we have an API instead of
procfs. :) This should let total resource use be tracked and also
allows qdel to actually kill all the processes associated with a job
instead of just the head as long as the execd_params variable includes
ENABLE_ADDGRP_KILL=true and tight integration is used in parallel
I'll eventually merge this upstream, but that will take time and I need
the feature in the port now.
This is based in part on work for Darwin and AIX support by Ron Chen.