long running workers

[mstephen19]

At the moment, a ThreadzWorker will exit its process and terminate once the worker function has returned a value (or its promise has resolved/rejected).

There should be an option to create a worker than can be "long-running", meaning that it doesn't exit its process unless you tell it to. These long-running workers would accept a map of keys, all of which would correspond to different options the worker could run.