"struct task_info" declaration

Conflicts:
	NEWS

work without a real cray system (pretty much what job_container/none used
to do.

a job container

Reverts part of commit cb378ae9

Conflicts:
	NEWS

at the same time.

The container owner should have been SlurmdUser rather than job
owner for Prolog, Epilog and UnkillableProgram parameters

Make sure the UnkillableStepProgram runs in a job container owned
by the job's owner.

If a job preemption involves multiple preemption types (cancel +
requeue + suspend) and more than one job is preempted with one
of the preemption types being suspend and the other something else,
the preemptee initiation may be delayed longer than needed.
bug 377