完善消息下发功能

消息下发功能太简单

1、消息下发可直接下发对象到终端（自动对象转换HEX）
2、消息下发应答处理-应可直接转换为定义的resquest对象。
3、应答消息可考虑放置redis等中，考虑下集群部署问题。

Currently when up/down tempo happens playback has to be stopped to dispose of the timeout event source for the old BPM. What should really happen is that the timeout should be disposed, a new one created and start emitting events seamlessly, resetting all tracks back to the start.

This should be accomplished while maintaining the playing state.