Created by: douglascayers
The Job.progress function acts as a getter and setter depending on the argument value passed to it.
In the context of a sandboxed job processor (forked process), the job instance given to the processor is actually a wrapped JSON message. The progress function on the wrapped job object only behaves as an asynchronous setter.
This pull request modifies the progress function on the wrapped job object to behave as both a getter and a setter.