- Replace an instance of a hardcoded /usr/X11R6 with $X11BASE. This was
detected by dosirak.kr.freebsd.org.
- Make use of the OPTIONS variable. Because of this, replace the
MUSICADDON and VOICEADDON switches with WITH_MUSIC and WITH_VOICE.
- Add support for OpenAL as wished by Peter Thoenen (eol1 at yahoo com).