1 - benq: options for specifying subject and other params
2 - benq: take job from file
4 - bprun: option for setting max # of running jobs
8 - Terminology: machine vs. host
10 - Detector of orphans (unused queue dirs, jobs on non-existent machines, non-queued jobs)
11 - job failed => give a more explanatory message
12 - write_job_status should be atomic