preparing 2.4.17 release updated and rebuilt the docs fixed a comment

* configure.in: preparing 2.4.17 release
* doc/*: updated and rebuilt the docs
* xpath.c: fixed a comment
* python/libxml.c: fixed a possible reentrancy problem
Daniel
diff --git a/xpath.c b/xpath.c
index 5baacf0..96b3916 100644
--- a/xpath.c
+++ b/xpath.c
@@ -3475,7 +3475,7 @@
  *
  * Create a new xmlXPathContext
  *
- * Returns the xmlXPathContext just allocated.
+ * Returns the xmlXPathContext just allocated. The caller will need to free it.
  */
 xmlXPathContextPtr
 xmlXPathNewContext(xmlDocPtr doc) {