Make PulseAudio unnecessary

[probonopd]

Currently PulseAudio needs to run on the FreeBSD for sound to work (e.g., in Spotify).
It would be nice if this requirement could be dropped, e.g., by having a tiny extension to the FreeBSD sound system that would mimic the parts of PulseAudio the Linuxulator needs for sound to work.

This work is outside of the scope of helloSystem, but we would like to incorporate it once a solution exists.