Allow directing a control command to a single host only, by adding a "destination" field contaning the workers hostname.
Allow directing a control command to a single host only, by adding a "destination" field contaning the workers hostname.

frac/celery,ask/celery,WoLpH/celery,ask/celery,cbrepo/celery,mitsuhiko/celery,frac/celery,cbrepo/celery,mitsuhiko/celery,WoLpH/celery