Commit Briefs
add an audio implementation for ALSA
it still doesn't work correctly, audio is very distorted, but at least there's some sound.
split out sndio-specific parts to audio_sndio.c
This hides the libsndio bits behind a small audio_* API for which in the future we may provide multiple implementations.
add DISTNAME variable
like the one from bsd.port.mk, here it's used to decide the name of the tarball.
use (a modified version of) kristaps' oconfigure
see GitHub issue #1
switch from libmad to libmpg123
libmpg123 is more "loud" than libmad, at least for the mp3s that I have around. Is also newer and maintained. I've heard is also faster, but amused is so simple that it doesn't make any difference.