Rewrite the entire audio support library on top of OpenAL rather than plib's

sound manager.  The interface was simplified and cleaned up a bit, and I
haven't back ported these changes to the plib sound wrappers ... we could
I suppose if someone really had a problem, but I haven't seen anything so
far that would indicate the extra effort is worth it.

configure.ac

@@ -270,7 +270,21 @@ esac
 opengl_LIBS="$LIBS"
 LIBS="$base_LIBS"
 
+dnl check for OpenAL libraries
+case "${host}" in
+*)
+    dnl default unix style machines
+
+    AC_SEARCH_LIBS(alGenBuffers, openal)
+    ;;
+
+esac
+
+openal_LIBS="$LIBS"
+LIBS="$base_LIBS"
+
 AC_SUBST(base_LIBS)
+AC_SUBST(openal_LIBS)
 AC_SUBST(opengl_LIBS)
 AC_SUBST(thread_LIBS)
 AC_SUBST(network_LIBS)