Problem reported by Coverity

The original logic in c69650a9
  was flawed. This commit removes that logic. New logic is still
  required for proper enforcement.

Remove DelayBoot configuration parameter from knl.conf and move to
  SchedulerParameters.
Set job default delay_boot value from configuration parameter
Enforce delay-boot scheduling logic.

Add job burst_buffer_state and delay_boot fields to scontrol and squeue
    output. Also add ability to modify delay_boot from scontrol.

Add salloc, sbatch and srun option of --delay-boot=<time>, which will
    temporarily delay booting nodes into the desired state for a job in the
    hope of using nodes already

Add job AdminComment field which can only be set by a Slurm administrator.

Add event trigger on burst buffer errors (see strigger man page,
    --burst_buffer option).

Insure reported expected job start time is not in the past for pending jobs.
bug 3002

burst_buffer/cray: Requeue, but do not hold a job which fails the pre_run
    operation.
bug 3009

Bug 2984.

Only mark job_id as zero for batch step (when all job steps would be
cleared), not for individual steps which prevented successive steps
from being cancelled.

Bug 2984.

Conflicts:
	META
	NEWS

slurmstepd modified to pre-load all relevant plugins at startup to avoid
    the possibility of modified plugins later resulting in inconsistent API
    or data structures and a failure of slurmstepd.
bug 2334

bug 2655

Add more details to the log messages for improved ability to
diagnose problems.

Bug 2983.

Continuation of 18947480. Commit cff2effc made cpu_freq_init
unconditionally set up the structures, so this reinitialization was
discarding the true original info, which prevents the frequency
and governor from being restored properly after the step completes.

Don't about step launch if job reaches expected end time while node is
    configuring/booting (NOTE: The job end time will be adjusted after node
    becomes ready for use).
bug 2985

The sleep starts at 0.1 second and doubles each time to a
  maximum value. Previous maximum was 2 seconds, increased
  to 5 seconds to account for very large KNL boot times
  (tens of minutes) and to limit overhead on slurmctld daemon.

If the KNL node modes reported by cnselect and capmc differ, log
  that using "info" rather than "debug".

Optionally lock slurmstepd in memory for performance reasons and to avoid
    possible SIGBUS if the daemon is paged out at the time of a Slurm upgrade
    (changing plugins). Controlled via new LaunchParameters options of
    slurmstepd_memlock and slurmstepd_memlock_all.
bug 2334