sort from GNU coreutils 5.2.1 doesn't accept the +- syntax

anymore. Hopefully the -k syntax is supported by all other
sort versions

tools/mergedirs

@@ -24,7 +24,7 @@ MODULES=`for a in $@ ; do
 		$cpp -U unix -D MACROS_ONLY -I $OBJDIR - |
 		sed "/^[ ]*\$/d;/^#/d;s@\\(.*\\)@\\1 $a/\\1@"
 		done |
-	sort +0 -1 -u |
+	sort -k1,1 -u |
 	cut -d ' ' -f 2`
 rm -rf $LIBDIR $CONFDIR
 mkdir -p $LIBDIR $CONFDIR