Setting up the framework for structured error reporting, touches a lot of

* HTMLparser.c c14n.c catalog.c error.c globals.c parser.c
  parserInternals.c relaxng.c valid.c xinclude.c xmlIO.c xmlregexp.c
  xmlschemas.c xpath.c xpointer.c include/libxml/globals.h
  include/libxml/parser.h include/libxml/valid.h
  include/libxml/xmlerror.h: Setting up the framework for structured
  error reporting, touches a lot of modules, but little code now
  the error handling trail has been cleaned up.
Daniel
diff --git a/c14n.c b/c14n.c
index a8030fa..01c46b1 100644
--- a/c14n.c
+++ b/c14n.c
@@ -132,7 +132,7 @@
 static void
 xmlC14NErrMemory(const char *extra)
 {
-    __xmlRaiseError(NULL, NULL, NULL, NULL, XML_FROM_C14N,
+    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_C14N,
 		    XML_ERR_NO_MEMORY, XML_ERR_ERROR, NULL, 0, extra,
 		    NULL, NULL, 0, 0,
 		    "Memory allocation failed : %s\n", extra);
@@ -154,7 +154,7 @@
 {
     if (ctxt != NULL)
         ctxt->error = error;
-    __xmlRaiseError(NULL, NULL,
+    __xmlRaiseError(NULL, NULL, NULL,
 		    ctxt, node, XML_FROM_C14N, error,
 		    XML_ERR_ERROR, NULL, 0,
 		    NULL, NULL, NULL, 0, 0, msg);
@@ -1490,7 +1490,7 @@
               int exclusive, xmlChar ** inclusive_ns_prefixes,
               int with_comments, xmlOutputBufferPtr buf)
 {
-    xmlC14NCtxPtr ctx;
+    xmlC14NCtxPtr ctx = NULL;
 
     if ((doc == NULL) || (buf == NULL)) {
 #ifdef DEBUG_C14N