parallel_processing.multiprocess_functions could be much simpler

[jairideout]

I think parallel_processing.multiprocess_functions could be simplified by using multiprocessing.Pool, since we're specifying a number of functions to be run, a number of processes, and then blocking until we have all of the results. Using a Pool, we can easily accomplish this with a parallel map.

@rybern do you see any issues with this versus what you have in place now? See this page for details.

[rybern]

Yep, I'm sure we could do this. I read about this after I finished my implementation, and decided it wasn't a priority since what I have works. If you want, I think this would be pretty easy to figure out.

[jairideout]

Not a high priority, but good to keep in mind for future cleanup.