This add some additional logic to the commit made to version 15.08
as needed for operation with version 16.04. Specifically, once a
persistent burst buffer is created in versioin 16.04 the create
flag is cleared to prevent attempts at duplicate buffer create.
A new "use" persistent burst buffer is added for our needs (indicating
that a DataWarp "paths" operation is required). The first commit
is 905ac850

burst_buffer/cray - Don't call Datawarp "paths" function if script includes
    only create or destroy of persistent burst buffer. Some versions of Datawarp
    software return an error for such scripts, causing the job to be held.
bug 2624

No change in any logic or definitions

Without these time limits and without time limits on the partitions,
the group usage limits become huge values and make validation of some
qos/association limit tests confusing

Bug 2601

When using NO_NHC, the step's job ptr would be nulled out before signalling the tasks.

I noticed that the CpuFreqDef config option was only partially implemented. The value was parsed, but the never used. So I took the liberty of re-purposing it to mean sort of the opposite, namely the frequency governor to use when running a job step in case the job doesn't explicitly provide any --cpu-freq option.

I also changed the default of the CpuFreqGovernors option to be "ondemand,performance", since ondemand isn't available with the intel_pstate driver.

Otherwise the patch should be relatively straightforward and only changes a few minor things here and there.

a) setpgrp() swapped for equivalent setpgid(0, 0)

b) define _GNU_SOURCE to unmask getline function definition in stdlib.h

The test was sensitive with respect to a batch step starting before
  requeuing the job. The batch step accounting record either appeared
  in the accounting records or did not depending upon timing. A sleep
  has been added after the job enters RUNNING state to make sure the
  batch steps starts and an accounting records is generated for it.

Include test ID in the account name to better identify where
  vestigial accounts come from.

Coverity reported:
    CID 93013:  Error handling issues  (CHECKED_RETURN)
	    "read(int, void *, size_t)" returns the number of bytes read, but it is ignored.

umask() is also not thread-safe.

While waiting for the HealthCheckProgram to succeed, slurmd can be
stopped. The previous behavior introduced a delay up to 10 seconds
between the shutdown request and the actual shutdown. This patch
removes this delay.

Intentially leave the key value fixed, rather than initialize from
from /dev/urandom as is commonly recommended. Slurm does not rely on
the hash function for any cryptographic functionality, and randomness
would make debugging harder if the hash key changed on each start.

Found by clang.

The job submit logic is not prepared to deal with deadline scheduling.
If a job is submitted with a deadline, defer it's scheduler to the
main scheduling loop or backfill scheduler, which has logic to manage
deadlines.

As part of the setup activity prior to invoking the CCM prologue on Cray native
Slurm systems, the job prolog_running value is incremented and the job_state is
OR'd with JOB_CONFIGURING.  After the CCM prologue completes, these field
changes are removed.  That setup activity allows the CCM prologue to complete
before the job launch continues.

If the slurmctld is shutdown or killed while a CCM prologue is executing, those
two job field changes can't be removed since slurmctld is no longer there.
Clearing those field values is now handled during job recovery within the
select/cray plugin select_p_job_init() procedure.  If a job being recovered came
from a CCM defined partition and if either of those two field values are still
set as above, then the CCM prologue is run again.

The CCM prologue handles being called more than once.  The above field changes
are then removed after this rerun CCM prologue completes.  The CCM epilogue is
not affected.

If a job was submitted with a deadline and no time_limit or min_time,
but the system has a QOS MaxWall the job's time_limit would be set
to the QOS limit. Since there is no min_time specified, the QOS MaxWall
would be treated as a min and max time limit for the job and potentially
make the deadline impossible to satisfy. Now we set the min_time to
1 minute of there is a deadline, but no time_limit or min_time.

Also make sure the job is cancelled at the end of the test

Add TopologyParam option of "TopoOptional" to optimize network topology
    only for jobs requesting it.
bug 2567

Timeout stalled transfers and cleanup related data structures. Default
to wait five minutes since last update. Hook onto registration/ping message
type to trigger cleanup in a minimally invasive manner.

While here restructure certain functions to use list_* functions
rather than iterate on the structures.

Otherwise --mail-type=ALL will send an unexpected stage_out message back
to the user.

Bug 2541.

Otherwise --mail-type=ALL will send an unexpected stage_out message back
to the user.

Bug 2541.

Siphash is a state of the art keyed hash function that is performance competitive with the usual non-cryptographic hash functions. It's used as the default hash function backing hash tables in e.g. Perl, Python, Rust, and so on. Here we initially use it for the gid cache hash table, and in the common xhash implementation.

sacctmgr list events

step_ptr->job_ptr is already dereferenced several times by now, so
null check is unnecessary here.