fix for better debugging when trying to start a new cluster in accounting that hasn't been added yet

add -n description to slurmd and slurmctld help message
fix support so that nice value of -2 is valid (-2 == NO_VAL).

    "scontrol update JobId=# NumNodes=#" or
    "scontrol update JobId=# NodeList=<names>". Subsequent job steps must
    explicitly specify an appropriate node count to work properly.

    daemon's nice value.

which gets group members

    See "man slurm.conf" for details about how these control when slurmctld
    updates its information of which users are in the groups allowed to use
    partitions.

ESLURM_REQUESTED_NODE_CONFIG_UNAVAILABLE when slurmctld has restarted and 
nodes have not yet registered (in unknown state).

 -- Add support for maximum node count in job step request.
 -- Fix bug in CPU count logic for job step allocation (used count of CPUS per
    node rather than CPUs allocated to the job).

updated documentation for the new purge options and made them backwards compatible with 0 meaning don't run

Applied patch from David Egolf (David.Egolf@Bull.com) Added the ability to purge/archive accounting data on a day or hour basis, previously it was only available on a monthly basis.

Altered srun to set max_nodes to min_nodes if not set when doing an allocation to mimic that which salloc and sbatch do.  If running a step if the max isn't set it remains unset.