Better handling of select plugins that don't exist on various systems for cross cluster communication.  Slurmctld, slurmd, and slurmstepd now only load the default select plugin as well.

Added preempt_mode option to qos.  Also added quite a bit of logic to add options for for new cpu_run_mins limits

    2.2.0.pre7.

   svn merge -r20596:20629 https://eris.llnl.gov/svn/slurm/branches/slurm-2.2.multi.partition

    triggers from working without the --enable-debug configure option.

   "sbatch --begin=uts458389988 my.script").

    srun/sbatch --hold/-H option or use "scontrol update jobid=# priority=0"
    to hold and "scontrol update jobid=# priority=1" to release).

    get purged before their trigger can be processed (e.g. MinJobAge=1).

    RLIMIT_STACK.

    job at submission time, but to attempt scheduling many jobs at once for
    improved performance under heavy load.

    than one port for improved scalability.

    reservations.