improved config parser and made status check more robust to tasks transiently disappearing.

The issue is really that it appears that sometimes NFS cannot see the completion file immediately after the job disappears from the active job list.  (Some form of race condition I assume)

Changed it so failures are reported as "Missing" for 5 seconds before they are declared as true failures.
Added missing file for sum_of_squares test
Wrote a file when job starts as well as when job terminates