src: remove unused include
src: use macros to reduce more boilerplate
src: pass in instance instead of relying on lookup
src: fix field count for call state event
src: remove unused symbols
src: add prefix to event symbol variables
src: DTMF->CALLDTMF
src: set REGSTATE symbols
src: fix style
src: remove global context reference
src: always set null sound device for now
src: silence erroneous compiler warnings
src: add missing HandleScopes
src: use 200 as default statusCode for answer()
src: add wrapper for AudioMedia objects
src: allow creating of AudioMediaPlayer/AudioMediaRecorder