Initial upstream fitlering implementation.

Test filter with up and down stream filtering. Keeps top N queries
and prints a report of these queries on session close.

server/modules/routing/readconnroute.c

@@ -688,7 +688,7 @@ clientReply(
 
 	ss_dassert(client != NULL);
 
-	client->func.write(client, queue);
+	SESSION_ROUTE_REPLY(backend_dcb->session, queue);
 }
 
 /**

server/modules/routing/readwritesplit/readwritesplit.c

@@ -1318,7 +1318,7 @@ static void clientReply(
         if (writebuf != NULL && client_dcb != NULL)
         {
                 /** Write reply to client DCB */
-                client_dcb->func.write(client_dcb, writebuf);
+		SESSION_ROUTE_REPLY(backend_dcb->session, writebuf);
 
                 LOGIF(LT, (skygw_log_write_flush(
                         LOGFILE_TRACE,