[STORM-1501] launch worker process exception will cause supervisor process exited

[caofangkun]

util.clj/async-loop default kill-fn will kill current process

when supervisor use util.clj/launch-process to launch worker process , if exeception occurs , supervisor process will exit.

[revans2]

I am a bit curious why we need this? What exception/error did you see come from the worker process?

[revans2]

Why are we throwing away error?

What happens if this does not exit? I assume that the heartbeat monitoring will detect it and do the right thing, but are there other places in the code besides a worker process that we use this? Will there be problems especially around the exit-code-callback if they are not called?