说明：  一个不用windows api实现的 UPNP NAT 工具类。用于在内网机器上远程配置网关上的NAT，需要网关支持uPnP协议（如xp操作系统就支持）
(a no windows api achieved UPnP NAT tools category. Including net for the machines remotely configure the NAT Gateway, the Gateway needs support Accessing agreements (for example, xp operating system support))