KAZOO-216: change dtmf listener to generic event listener, provide tracking and cleanup
KAZOO-216: change refs from dtmf to event listener
KAZOO-216: pass events to interested FSMs and regular PIDs
KAZOO-216: add ability for custom relay function
KAZOO-216: move recording listener to whistle_media
KAZOO-216: start the wh_media_recording server
KAZOO-216: use proc_lib to spawn
KAZOO-216: add ability to enter a gen_listener loop
KAZOO-216: move recording helpers to wh_media_recording

allow starting non-traditionally with enter_loop
KAZOO-216: clean up cf_record_call to only start the wh_media_listener process
KAZOO-216: more gracefully cleanup events
KAZOO-216: rename state var to is_recording, and maybe start recording once the gen_listener is ready
KAZOO-216: add call recording konami code
KAZOO-216: extract state before entering loop
KAZOO-216: add specs, formatting