feat(third_party/lisp/s-xml): Check in sources & derivation

Checked in the sources for this because it is tracked upstream in CVS
and I can't be bothered to deal with that right now.

third_party/lisp/s-xml/examples/remove-markup.lisp

@@ -0,0 +1,21 @@
+;;;; -*- mode: lisp -*-
+;;;;
+;;;; $Id: remove-markup.lisp,v 1.1 2004/06/11 11:14:43 scaekenberghe Exp $
+;;;;
+;;;; Remove markup from an XML document using the SSAX interface
+;;;;
+;;;; Copyright (C) 2004 Sven Van Caekenberghe, Beta Nine BVBA.
+;;;;
+;;;; You are granted the rights to distribute and use this software
+;;;; as governed by the terms of the Lisp Lesser General Public License
+;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
+
+(in-package :s-xml)
+
+(defun remove-xml-markup (in)
+  (let* ((state (make-instance 'xml-parser-state
+                              :text-hook #'(lambda (string seed) (cons string seed))))
+         (result (start-parse-xml in state)))
+    (apply #'concatenate 'string (nreverse result))))
+
+;;;; eof