applied a patch from Gman for building docs applied a patch from Gary

* doc/*: applied a patch from Gman for building docs
* valid.c xmllint.c include/libxml/valid.h: applied a patch from
  Gary Pennington to provide an allocator for xmlValidCtxt
* xmlreader.c: applied patch from Jacek Konieczny fixing bug
  #113580 about data not being passed immediately.
Daniel
diff --git a/xmlreader.c b/xmlreader.c
index 4d37165..20ff753 100644
--- a/xmlreader.c
+++ b/xmlreader.c
@@ -688,6 +688,8 @@
     do {
         if (xmlTextReaderGetSuccessor(reader->node) != NULL)
 	    return(1);
+	if (reader->ctxt->nodeNr <= reader->depth)
+	    return(1);
 	if (reader->mode == XML_TEXTREADER_MODE_EOF)
 	    return(1);
 	val = xmlTextReaderPushData(reader);