Task/cray: Treat missing "mems" cgroup with "debug" messages rather than
    "error" messages. The file may be missing at step termination due to a
    change in how cgroups are released at job/step end.

Was added in 6cfa534f
Was broken in c1513956

When the batch step is launched the node would complain that another
batch step already exists and drain the node. Since this isn't being
used or is documented, this is being removed.

Honor --ntasks-per-node and --ntasks option when used with job constraints
    that contain node counts.
bug 3458

Defer interactive job allocation until ALL allocated nodes are ready
  rather than after PrologSlurmctld (if any) completes.

Bug 3467.

bug 1949

Add scancel "--hurry" option to avoid staging out any burst buffer data.
bug 3462

Only available in squeue with the '-O lastschedeval' format
option, no single-character option provided.

Bug 3122.

Update the timestamp when job is considered in main scheduler or
backfill.

Bug 3122.

This part wasn't supposed to go into this commit.

burst_buffer/cray - Do not execute "pre_run" operation until after all nodes
    are booted and ready for use.
bug 3461

partitions.

This reverts commit 843df527.