Put virtual_oss, /etc/devd/snd.conf and the other audio-related tools
into a new "sound" package. Don't create a separate -lib package,
since it's unlikely someone will want mixer(3) without mixer(8).
Put the sound package in the optional set rather than minimal, since
it's not actually required for audio hardware support, and many systems
(including nearly all servers) won't want it installed.