patch for supported mobility and MPLS. in NS2

利用tiger 数据库，构建一个实际道路地图作为仿真场景，借助SUMO 交通仿真器和NS2 网络仿真平台，评估ADOV、DSR、 DSDR 3 种路由协议在城市场景车载自组网(VANET)中的适用性-This paper refers tiger database, builds a realistic road map as simulation scene. It evaluates the applicability of three routing protocols inc