make Valley into Configurable and move SubmitWorkersMax into Valley's context, because it is more "global" than a Meadow

simplification of the interface: scripts no longer understand --user/--password/--host/--port/--database and require --url instead

capture Worker's death message during the new 'SPECIALIZATION' status in job_message/msg (thanks, Thomas!)

feature: jobless workers will now leave module compilation errors in the job_message table (thanks, Kathryn!)

bugfix: worker.log_dir varchar(80) was too limiting, now extended to varchar(255); (thanks, Kathryn!)

bugfix: make sure we release claimed jobs from a manually-run worker whose Runnable fails at compilation (thanks, Miguel!)

bugfix: query in Q::fetch_all_dead_workers_with_jobs() has to reference worker table by its full name

clearer display of job_counters on the graph; removed misleading and unused remaining_job_count() and cpu_minutes_remaining()

merge reset_and_grab into one subroutine; pre-increment dependent semaphore if re-running a DONE job; use -force flag for force-running an individual job

moved special-job-reset and special-job-reclaim into the same call, removed the unnecessary fetch in between