also return -1 in more failure cases

Coverity CID 188689

Also simplify this xstrfmtcat() into an xstrcat() call while here.

Bug 5828.

This fixes some problems with job steps that allocate subsets of
the job's GRES allocation.

add logic so that a job step can be allocated subsets of the job's
GRES allocation, even when the GRES specifications differ. For example,
the job can specifiy gres-per-node and the step gres-per-task.

Update slurm.spec and slurm.spec-legacy as well.

Update slurm.spec and slurm.spec-legacy as well.

Bug 5479

Bug 5553

Bug 5744

Bug 5476.

SLURM_FAILURE removed in a76a9486.

Leads to false-positive warnings about settings being too low when
they're actually fine. E.g., if innodb_buffer_pool_size is over 2GB
the warning would have been printed in error.

Bug 5661.

Bug 5594.

You should not make RPC calls within MailProg (or anything else
fork()+exec()'d from slurmctld), so use the environment variable that
is now exposed instead.

Bug 5443.

smail currently uses 'scontrol show config' to get this data; making RPC
calls within programs fork()+exec()'d from slurmctld is best avoided as
it amplifies RPC load on the controller.

Bug 5443.

Fix formatting on the log_level documentation block as well.

Bug 5399.

Add info to man page as well.

Bug 4961.

Bug 5724