Allow logging of received XML prior to parsing and processing

While trying to debug an inbound request containing invalid xml we
realized there was no way to log the raw xml since the xml parser
throws an error before the logging function is called

Author: Deividy

lib/server.js

@@ -100,11 +100,13 @@ Server.prototype._requestListener = function(req, res) {
         gunzip = null;
       }
       try {
+        if (typeof self.log === 'function') {
+          self.log("received", xml);
+        }
         self._process(xml, req.url, function(result) {
           res.write(result);
           res.end();
           if (typeof self.log === 'function') {
-            self.log("received", xml);
             self.log("replied", result);
           }
         });