XmlNodes are now always closed

Remove the close() method and closed attribute. Remove all the calls to
close().  (Save one bool per XmlNode, yay, and save a few ifs and some
useless function calls. At best it should be unnoticeably faster and lighter
and save a few keystrokes in the future)

louloulibs/xmpp/xmpp_parser.cpp

@@ -104,7 +104,6 @@ void XmppParser::end_element(const XML_Char* name)
 {
   (void)name;
   level--;
-  this->current_node->close();
   if (level == 1)
     {
       this->stanza_event(*this->current_node);