Revert "Move all external code to lib/external."

This reverts commit 9effec0c4e.

lib/fetch/errlist.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+# $NetBSD: errlist.sh,v 1.2 2008/10/06 12:58:29 joerg Exp $
+
+printf "static struct fetcherr $1[] = {\n"
+while read code type msg; do
+	[ "${code}" = "#" ] && continue
+	printf "\t{ ${code}, FETCH_${type}, \"${msg}\" },\n"
+done < $3
+
+printf "\t{ -1, FETCH_UNKNOWN, \"Unknown $2 error\" }\n"
+printf "};\n"