OASIS RelaxNG testsuite python script to run regression against OASIS

* test/relaxng/OASIS/spectest.xml: OASIS RelaxNG testsuite
* check-relaxng-test-suite.py: python script to run regression
  against OASIS RelaxNG testsuite
* relaxng.c: some cleanup tweaks
* HTMLparser.c globals.c: cleanups in comments
* doc/libxml2-api.xml: updated the API
* result/relaxng/*: errors moved files, so large diffs but
  no changes at the semantic level.
Daniel
diff --git a/globals.c b/globals.c
index 2a50a08..c4eb3f5 100644
--- a/globals.c
+++ b/globals.c
@@ -464,7 +464,9 @@
  * xmlRegisterNodeDefault:
  * @func: function pointer to the new RegisterNodeFunc
  *
- * Returns the previous value of the registration function
+ * Registers a callback for node creation
+ *
+ * Returns the old value of the registration function
  */
 xmlRegisterNodeFunc
 xmlRegisterNodeDefault(xmlRegisterNodeFunc func)
@@ -479,6 +481,8 @@
  * xmlDeregisterNodeDefault:
  * @func: function pointer to the new DeregisterNodeFunc
  *
+ * Registers a callback for node destruction
+ *
  * Returns the previous value of the deregistration function
  */
 xmlDeregisterNodeFunc