initial functional addition of real-time audio support. The existing codebase used a blocking I/O API called "gen audio", which I was unable to find documentation for. This was replaced by the OpenBSD sndio(7) audio interface.

Initially, I am using the blocking I/O calls of sndio as it matches the existing codebase implementation. However it appears that this is causing under/overruns in the audio buffers. I will be changing this to use non-blocking I/O calls.