core/configuration.py:  Added a new 'multiprocessing_workers' setting/CLI option that controls how many cores Gate One will use when using multiprocessing.  If set to 0 it will disable multiprocessing altogether.  Note that disabling multiprocessing can actually *increase* memory usage since Gate One doesn't keep unused multiprocessing processes alive for long (30 seconds if idle by default).
core/server.py:  Relocated some things related to the CPU_ASYNC global in order to support the new 'multiprocessing_workers' setting.
onoff.py:  Modified the way `OnOffMixin.trigger()` works slightly in order to improve performance.  Also, when debug logging is enabled the args/kwargs output won't be enormously long anymore.