Treat invalid user ID in AllowUserBoot option of knl.conf file as error
    rather than fatal (log and do not exit).

Prevent slurmctld abort if job is killed or requeued while waiting for
    reboot of its allocated compute nodes. The _wait_boot() would
    reference job_ptr->node_bitmap, which would be NULL.

Bug 2908

Step hasn't been assigned resources, so the select_jobinfo struct
hasn't yet been populated. Calling select_g_step_finish will dereference
causing a segfault.

Bug 2922.

Happens when there are running jobs on the cluster.

If the user is now allowed to use the partition,
    then do not check that user's group access again for 5 seconds.
bug 2913

Improve partition AllowGroups caching. Update the table of UIDs permitted to
    use a partition based upon it's AllowGroups configuration parameter as new
    valid UIDs are found rather than looking up that user's group information
    for every job they submit, which can involve considerable overhead for
    some systems.
bug 2913

Minimize preempted jobs for configurations with multiple jobs per node.
  Previous logic would preeempt every job on node allocated to pending
  job.
bug 2906

Fix for core selection with job --gres-flags=enforce-binding option.
    Previous logic would in some cases allocate a job zero cores, resulting in
    slurmctld abort.
bug 2808

In commit b8190e5d many places that were mean to be pending step ids
were changed to be extern_step id.  The main problem was when we came up
with the idea of the extern step we reused -1 (INFINITE) for the id.  So
pending steps also appeared to be extern steps as well.  Hopefully this
fixes the situation.

Bug 2907

Start power save thread only after the partition information is read
  in order to avoid trying to interpret the SuspendExcParts configuration
  information before the partition information is available, which would
  result in a slurmctld abort.

bug 2900

Before it was showing it as TBD since pending steps and the extern step
have the same stepid.

Fix gang scheduling and license release logic if single node job killed on
    bad node. Notifying gang and releasing licences is normally done when
    the epilog completion happens, but if the node(s) assigned to a job are
    all down, that does not happen. This results in the licenses being
    reserved indefinitely and the gang scheduler being left with a bad
    (old) job pointer that can result in various failure modes
bug 2867

anyway to attempt to log the backtraces of the potential
unkillable processes.

processes.

Bug 2892.

Bug 2874

We will most likely redo this logic (as it appears to be duplicated) in
a following patch.

bug 1884

Don't generate an error when a batch job is submitted that must wait
  for stage-in before starting.

Bug 2886

Add new SchedulerParameters option of bb_array_stage_cnt=# to indicate
    how many pending tasks of a job array should be made available for burst
    buffer resource allocation.
bug 1884

Was incorrectly translating request to job.extern if part of a
comma-separate list.

Bug 2890.

bug 2858

(regression in 16.05.2).

related commit 5d3e5e1e

Bug 2612 and 2886

Document limitations in burst buffer use by the salloc command (possible
    access problems from a login node).
bug 2883

task/cgroup plugin is configured with ConstrainRAMSpace=yes, then set soft
    memory limit to allocated memory limit (previously no soft limit was set).
bug 2679

of 0.

This might be the cause of run away jobs.  I couldn't see how an end_time
could be 0, but if it was it would just exit and never set time_end to
anything.  At least if it happens now we can have an idea that it is
possible and we will have an idea this is the place it happens.

This will keep from referencing the task array that might not be set up
correctly in src/common/plugstack.c _spank_handle_init().

Prevent possible incorrect counting of GRES of a given type if a node has
    the multiple "types" of a given GRES "name", which could over-subscribe
    GRES of a given type.
bug 2836

cleaning up on a restart.