xlink: Deprecate remaining public function

This was never finished.

include/libxml/xlink.h

@@ -3,7 +3,7 @@
  * 
  * @brief unfinished XLink detection module
  * 
- * unfinished XLink detection module
+ * This module is deprecated, don't use.
  *
  * @copyright See Copyright for the status of this software.
  *
@@ -179,6 +179,7 @@ XMLPUBFUN void
 /*
  * Link detection module itself.
  */
+XML_DEPRECATED
 XMLPUBFUN xlinkType
 		xlinkIsLink		(xmlDocPtr doc,
 					 xmlNodePtr node);

xlink.c

@@ -93,6 +93,8 @@ xlinkSetDefaultDetect	(xlinkNodeDetectFunc func) {
  * @param doc  the document containing the node
  * @param node  the node pointer itself
  *
+ * @deprecated The XLink code was never finished.
+ *
  * Check whether the given node carries the attributes needed
  * to be a link element (or is one of the linking elements issued
  * from the (X)HTML DtDs).