Removed LLXMLNode::writeHeaderToFile

Isn't used. This header is written else where already,
and will be written from now on (also) by AIXML*, which
will be committed next.

indra/llxml/llxmlnode.h

@@ -157,11 +157,6 @@ public:
 	
 	static bool getLayeredXMLNode(LLXMLNodePtr& root, const std::vector<std::string>& paths);
 	
-	
-	// Write standard XML file header:
-	// <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
-	static void writeHeaderToFile(LLFILE *out_file);
-	
 	// Write XML to file with one attribute per line.
 	// XML escapes values as they are written.
     void writeToFile(LLFILE *out_file, const std::string& indent = std::string(), bool use_type_decorations=true);