0.11.1 bug fix release

   +  Made web front-end for job monitoring a separate script, ``gridmap_web``,
      since it can be used to talk to any ``JobMonitor`` instance. (Fixes #14)
   +  Fixed crash if a stalled job comes back from the dead (#15).
   +  Fixed crash if job's hostname is somehow not in white list and the job
      needs to be resubmitted (#16).
   +  Fixed crash from trying to set ``matplotlib`` back-end multiple times.
   +  Cleaned up some imports and removed some unused variables.