XInclude and other stuff while travelling. Contributed patches:

- tree.[ch] xinclude.[ch] xmllint.c configure.in valid.c
  debugXML.c xmlversion.h.in: Started adding XInclude support,
  this is a new xmllint option
- tree.c xpath.c: applied TOM patches for XPath
- xpointer.c: fixed a couple of errors.
- uri.c: added an escaping function needed for xinclude
- testXPath.c hash.c HTMLtree.c: minor cleanups raised by
  new warning from RH70 gcc's version
Daniel

valid.c

@@ -3212,6 +3212,7 @@ xmlSprintfElementChilds(char *buf, xmlNodePtr node, int glob) {
             case XML_DOCUMENT_TYPE_NODE:
             case XML_DOCUMENT_FRAG_NODE:
             case XML_NOTATION_NODE:
+	    case XML_NAMESPACE_DECL:
 	         strcat(buf, "???");
 		 if (cur->next != NULL)
 		     strcat(buf, " ");
@@ -3223,6 +3224,8 @@ xmlSprintfElementChilds(char *buf, xmlNodePtr node, int glob) {
 	    case XML_ELEMENT_DECL:
 	    case XML_ATTRIBUTE_DECL:
 	    case XML_ENTITY_DECL:
+	    case XML_XINCLUDE_START:
+	    case XML_XINCLUDE_END:
 		 break;
 	}
 	cur = cur->next;