API List Intervals

.. add an intervals=true|false to the fetch
   ride list URL to enable fetching of interval
   metrics as well as ride metrics.

   e.g.
   http://localhost:12021/athlete?intervals=true&metrics=Work,IF

httpserver/httpresponse.cpp

@@ -13,6 +13,7 @@ HttpResponse::HttpResponse(QTcpSocket* socket) {
     sentLastPart=false;
     buffersize=40960;
     barry.reserve(40960);
+    userdata_=NULL;
 }
 
 void HttpResponse::setHeader(QByteArray name, QByteArray value) {