added support and APIs needed for the catalog PI cleanup Daniel

* include/libxml/catalog.h include/libxml/parser.h
  include/libxml/xmlerror.h catalog.c parser.c parserInternals.c
  xmlIO.c: added support and APIs needed for the catalog PI
* include/libxml/xmlIO.h: cleanup
Daniel
diff --git a/include/libxml/xmlerror.h b/include/libxml/xmlerror.h
index 53c5751..88daeff 100644
--- a/include/libxml/xmlerror.h
+++ b/include/libxml/xmlerror.h
@@ -132,7 +132,8 @@
     XML_ERR_ENTITY_LOOP, /* 89 */
     XML_ERR_ENTITY_BOUNDARY, /* 90 */
     XML_ERR_INVALID_URI, /* 91 */
-    XML_ERR_URI_FRAGMENT /* 92 */
+    XML_ERR_URI_FRAGMENT, /* 92 */
+    XML_WAR_CATALOG_PI  /* 93 */
 }xmlParserErrors;
 
 /*