Do the bare minimum to provide a toggle for sndio support

--- configure.orig	2004-02-23 21:36:21 UTC
+++ configure
@@ -27912,7 +27912,30 @@ echo "$as_me: error: cannot use both --with-$audio and
 
 fi;
 
+want_sndio=yes
 
+# Check whether --with-esd or --without-esd was given.
+if test "${with_sndio+set}" = set; then
+  withval="$with_sndio"
+
+    case "$withval" in
+	yes)
+	    if test "$audio" = unknown
+	    then
+		audio="sndio"
+	    else
+		{ { echo "$as_me:$LINENO: error: cannot use both --with-$audio and --with-esd" >&5
+echo "$as_me: error: cannot use both --with-$audio and --with-esd" >&2;}
+   { (exit 1); exit 1; }; }
+	    fi
+	    ;;
+	no)
+	    want_sndio=no
+	    ;;
+    esac
+
+fi;
+
 if test "$audio" = unknown
 then
     case "$host" in
@@ -28252,6 +28275,10 @@ else
     fi
 fi
 
+if test "$audio" = sndio && test "$want_sndio" = yes
+then
+    ldadd_audio="$ldadd_audio -lsndio"
+fi
 
 if test "$audio" = unknown
 then