Bug fixes and an extension found and required by XSLT:

- xpath.c: bug fixes found from XSLT
- tree.c: preserve node->name special values when copying nodes.
- parserInternals.[ch] parser.[ch] SAX.c : added a mode where
  external subset are fetched when available but without full
  validation. Added xmlLoadExtDtdDefaultValue, need a function.
- HTMLtree.c: add support for xmlStringTextNoenc for XSLt HTML
  output with encoding disabled.
Daniel

include/libxml/parser.h

@@ -185,6 +185,8 @@ struct _xmlParserCtxt {
     int                nodemem;       /* Speed up large node parsing */
     int                pedantic;      /* signal pedantic warnings */
     void              *_private;      /* For user data, libxml won't touch it */
+
+    int                loadsubset;    /* should the external subset be loaded */
 };
 
 /**