comments cleanups use xmllint for doing the RelaxNG tests preparing 2.5.2

* HTMLparser.c tree.c xmlIO.c: comments cleanups
* Makefile.am: use xmllint for doing the RelaxNG tests
* configure.in: preparing 2.5.2 made schemas support default to
  on instead of off
* relaxng.c: removed the verbosity
* xmllint.c: added --relaxng option
* python/generator.py python/libxml_wrap.h: prepared the integration
  of the new RelaxNG module and schemas
* result/relaxng/*: less verbose output
Daniel
diff --git a/relaxng.c b/relaxng.c
index da83558..114167d 100644
--- a/relaxng.c
+++ b/relaxng.c
@@ -47,10 +47,10 @@
     (xmlStrEqual(node->ns->href, xmlRelaxNGNs)))
 
 
-#define DEBUG 1                 /* very verbose output */
-#define DEBUG_CONTENT 1
-#define DEBUG_TYPE 1
-#define DEBUG_VALID 1
+/* #define DEBUG 1 */                /* very verbose output */
+/* #define DEBUG_CONTENT 1 */
+/* #define DEBUG_TYPE 1 */
+/* #define DEBUG_VALID 1 */
 /* #define DEBUG_INTERLEAVE 1 */
 
 #define UNBOUNDED (1 << 30)
@@ -5407,6 +5407,11 @@
     ctxt->doc = doc;
 
     ret = xmlRelaxNGValidateDocument(ctxt, doc);
+    /*
+     * TODO: build error codes
+     */
+    if (ret == -1)
+	return(1);
     return(ret);
 }