Cray PMI refinements

Refine commit 5f89223fe8457795bb2e66caebe39e5f90584e61 based upon
feedback from David Gloe:
* It's not only MPI jobs, but anything that uses PMI. That includes MPI,
shmem, etc, so you may want to reword the error message.
* I added the terminated flag because if multiple tasks on a node exit,
you would get an error message from each of them. That reduces it to one
error message per node. Cray bug 810310 prompted that change.
* Since we're now relying on --kill-on-bad-exit, I think we should update
the Cray slurm.conf template to default to 1 (set KillOnBadExit=1 in
contribs/cray/slurm.conf.template).
bug 1171