There appears to be a bug in slurmstepd's task_exec.c parsing of the
multi-prog script when commands have no command line parameters.

srun is also broken in this respect, it is not slaunch specific.

honoring the overcommit flag.

The "--threads" option is now named "--pmi-threads", since it only applies
to PMI threading.  At this time slaunch has no other threading which might
requiring throttling.

made step_spec->overcommit 0 out cpu_count when creating a step so we don't check for avaliable processors. making it overcommit

Fix batch environment variable setting.

with sbatch.

in the future).

named.  It is really the number of cpus per node.

Have slaunch's return be the maximum task return code.