Detect FreeBSD, NetBSD and OpenBSD in the makefile. Add cdaudio support via
cd_bsd.c. I also had to add the track argument to the IsPlaying driver
function, as BSD uses it in the ioctl. Thanks to Alejandro Pulver for the
doing the original FreeBSD port.
Signed-off-by: Tyrann <tyrann@disenchant.net>
