Nextdoor/kingpin — pull request #122 by siminm (2014-10-27 23:43:24+00:00)
Title: Only raise exceptions during total failure

* This reworks every Actor to return False on during normal failures
-- This means the actor tries its job and fails.

* Exceptions are raised only for unmanageble conditions (when the actor
can't attempt its job, or does not understand what you want from it).