* [Engine] rename cls to AudioClassification
* [Engine] add android && vad demo

* vad recipe ok

* refactor vad, add vad conf, vad inerface, vad recipe

* format

* install vad lib/bin/inc

* using cpack

* add vad doc, fix vad state name

* add comment

* refactor fastdeploy download

* add vad jni; format code

* add timer; compute vad rtf; vad add beam param

* andorid find library

* fix log; add vad rtf

* fix glog

* fix BUILD_TYPE bug

* update doc

* rm jni