MCO-475 Reraise uncaught exceptions in the receiver_thread to the main thread

If an uncaught exception happens in the body of the reciever_thread
it simply exits unlogged.  With this commit we catch exceptions
raised in this thread and reraise them in the main thread (unless
we're pausing, as we just killed the thread and don't want it
shooting back)
Merge pull request #243 from richardc/MCO-475-runner_exceptions

MCO-475 Reraise uncaught exceptions in the receiver_thread to the main t...