bin/map: Use multiprocessing instead of pp for parallel processing because it's easier to use (it uses the Python threading API and doesn't require providing all the functions a task calls). Allow the user to set the cpus option to to use all system CPUs (needed because in test mode, the default is 0 CPUs to turn off parallel processing).
bin/map: Use multiprocessing instead of pp for parallel processing because it's easier to use (it uses the Python threading API and doesn't require providing all the functions a task calls). Allow the user to set the cpus option to to use all system CPUs (needed because in test mode, the default is 0 CPUs to turn off parallel processing).