1.最开始是LavaRtcEngine.h，LavaRtcEngineImpl.h

2.然后添加第三方webrtc库

3.cmakelist.txt:

build_lava.bat:

4.然后添加LavaRtcMediaFactory.h/cpp

形成最简单的结构：
lava/api

	LavaRtcEngine.h

lava/src

	LavaRtcEngineImpl.cpp
	LavaRtcEngineImpl.h
	LavaRtcMediaFactory.h
	LavaRtcMediaFactory.cpp
	LavaRtcLog.cpp

5.新增lava/demo

lava/demos/
		
	windows/nrtc_g2_demo
	android/lava_demo