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.

polling

Fixed slurm_load_slurmd_status and slurm_pid2jobid to work correctly when multiple slurmds are in use.

    to restrict spawned task nice values to that of the slurmd daemon plus 1.
    This insures that the slurmd daemon always have a higher scheduling
    priority than spawned tasks.

set down based upon slurm.conf state.

always return 0 for users that run sudo before scontrol (only user root
or SlurmUser can change node state, so we'd loose information otherwise
available).

    dependencies (e.g. job 12 dependent upon job 11 AND job 11 is dependent
    upon job 12). 

    verify the slurm.conf is the same as the one it is running.  If not an
    error message is displayed.  To silence this message add NO_CONF_HASH
    to DebugFlags in your slurm.conf.