Provide limited support for the MemSpecLimit configuration parameter without
    the task/cgroup plugin.

Revise commit e6ef1f0c
The root cause of the failure is a bug in HWLOC that has since
been fixed in HWLOC version 1.11.5.

If the second call to getgrouplist() found additional groups,
ngroups will be overwritten with this new larger value, while
the gids list would be truncated. (ngroups is a value-result arg.)
This will then lead to _gids_cache_lookup() returning the wrong
number of groups including invalid parts of memory, which are likely
to include some zeros.

Those zeros could then make it to the setgroups() call and thus
give the user access to the root group. Especially as setgroups
will succeed as long as the array does not contain -1 as a gid.

Bug 3320.

task/cgroup - Change error message if CPU binding can not take place to
    better identify the root cause of the problem. Specifically, if
    the hwloc_get_obj_below_by_type() function call completely fails
    that is likely due to task/affinity not being configured, so
    cpusets are not configured. Previous message was
    "task/cgroup: task[%u] infinite loop broken while trying to provision compute elements using %s (bitmap:%s)"
    The new message is
    "task/cgroup: hwloc_get_obj_below_by_type() failing, task/affinity plugin also required"

uint32_t needs %u on 32-bit platforms. Noticed by clang/travisci.

Test would fail if more than one task per core and SelectTypeParamers
  included CR_ONE_TASK_PER_CORE

Bug 3258

This reverts commit 55cb7973.

This reverts commit 817c2ca4.

# Conflicts:
#	NEWS

The test is still failing for me (along with a bunch of others),
  but this change at least gets the test started.

a slurmctld restart or reconfig, as they aren't really error messages.

Bug 3258

Bug 3258

Done jost to run "git push" again after internal github error on
  previous push:
remote: Resolving deltas: 100% (4/4), completed with 4 local objects.
remote: Unexpected system error after push was received.
remote: These changes may not be reflected on github.com!
remote: Your unique error code: bdecb7b0f321368fe1f037a81a6e9c2c

This restores the socket count check at node registration for
  non-KNL systems (at least systems without NodeFeaturesPlugins
  type that includes "knl"). This is a refinement of commit
  1ce9a7c4

Note that this does not protect against all possible problems here.
The setgroups() call in Linux at least is willing to set any gid_t
value except -1 on a group, so calls will not always fail on corrupted
group lists.

Bug 3320.

Remove uncached _get_grouplist() call which was only used here.

Bug 3315.

test12.2 was consistently failing on smd# cluster with tiny differences
  in the disk read and written. This change permits those tiny discrepancies
  to exist without failing the test.
  Here are the numbers, which are consistent:

  sacct --noheader -p --job=763.0 --format MaxDiskWrite,AveDiskWrite,MaxDiskRead,AveDiskRead
  10.00M|10.00M|10.03M|10.03M|
  (i.e. 0.3% discrepancy, up to 0.5% allowed with current code)

Test was failing due to hitting the memory limit (at least on smd1).

There were already several configurations that could cause this test
  to fail. I just added another.