Bug 462, http://bugs.skysql.com/show_bug.cgi?id=462, testall target fails in server/test to invalid MAXSCALE_HOME path specification.

Fixed path specification in server/test/makefile.

Added comments to mysql_backend.c

server/modules/protocol/mysql_backend.c

@@ -502,7 +502,10 @@ static int gw_read_backend_event(DCB *dcb) {
                                 goto return_rc;
                         }
                 }
-                /** If protocol has command set it is session command */
+                /** 
+                 * If protocol has session command set, concatenate whole 
+                 * response into one buffer.
+                 */
                 if (protocol_get_srv_command((MySQLProtocol *)dcb->protocol, false) != 
                         MYSQL_COM_UNDEFINED)
                 {