release of 2.4.20 updated and rebuilt the docs Daniel

* configure.in: release of 2.4.20
* doc/*: updated and rebuilt the docs
Daniel
diff --git a/python/libxml2class.txt b/python/libxml2class.txt
index 4b08b79..9e55c35 100644
--- a/python/libxml2class.txt
+++ b/python/libxml2class.txt
@@ -144,6 +144,12 @@
 normalizeURIPath()
 parseURI()
 
+# functions from module valid
+validateNameValue()
+validateNamesValue()
+validateNmtokenValue()
+validateNmtokensValue()
+
 # functions from module xmlIO
 cleanupInputCallbacks()
 cleanupOutputCallbacks()