1. I submit a first job that uses 1 GPU:
$ srun --gres gpu:1 --pty bash
$ echo $CUDA_VISIBLE_DEVICES
0

2. while the first one is still running, a 2-GPU job asking for 1 task per node
waits (and I don't really understand why):
$ srun --ntasks-per-node=1 --gres=gpu:2 --pty bash
srun: job 2390816 queued and waiting for resources

3. whereas a 2-GPU job requesting 1 core per socket (so just 1 socket) actually
gets GPUs allocated from two different sockets!
$ srun -n 1  --cores-per-socket=1 --gres=gpu:2 -p testk --pty bash
$ echo $CUDA_VISIBLE_DEVICES
1,2

With this change #2 works the same way as #3.
bug 1725

option.

Only going to do this in the master as it may affect scripts.

This reverts commit 454f78e6.

Conflicts:
	NEWS

bug 1724

Previously the test would generate an error if the default partition
  contained less than 3 nodes
bug 1720

switch/cray: Refine logic to set PMI_CRAY_NO_SMP_ENV environment variable.
Rather than testing for the task distribution option, test the actual
task IDs to see fi they are monotonically increasing across all nodes.
Based upon idea from Brian Gilmer (Cray).

afterward cause a divide by zero error.

corruption if thread uses the pointer basing validity off the id.

Bug 1710

Disable test with select/linear and only one node

Bug 1495

Correct count of CPUs allocated to job on system with hyperthreads.
The bug was introduced in commit a6d3074d
On a system with hyperthreads:
srun -n1 --ntasks-per-core=1 hostname
you would get:
slurmctld: error: job_update_cpu_cnt: cpu_cnt underflow on job_id 67072

preempt/job_prio plugin: Implement the concept of Warm-up Time here. Use
the QoS GraceTime as the amount of time to wait before preempting.
Basically, skip preemption if your time is not up.

-W/--wait is only supported by srun and should not show
up in the usage string of sbatch or salloc.

a job runs past it's time limit.

Bug 1705