Add power management and inter-cluster options

 -- Add job submission command options: --sicp (available for inter-cluster
    dependencies) and --power (specify power management options) to salloc,
    sbatch, and srun commands.
 -- Add DebugFlags option of SICP (inter-cluster option logging).
 -- Added DebugFlags value "SICP".
 -- Added job_descriptor field of "cluster".