C++ example and more

[chenguoguo]

1. Added C++ example
2. Separated swig part and example part
3. Fixed model bug where a personal model was used for snowboy.umdl

[standarddeviant]

This looks great - thank you for the demo.cc file. Is there any chance that a demo could be included for wav file input?

[chenguoguo]

@standarddeviant did you mean doing the detection for the input wav file instead of capturing audio using PortAudio? That might be a better idea. Anyway using wav file as input is possible. I didn't do it because reading the wav file also need some extra code (especially if you want to read it in a proper way...). But PRs are welcome for this! I can help if you have any questions.

[chenguoguo]

BTW @standarddeviant, if you want to do the detection for the input wav file, what you have to do is to read the wav as , and then run the detection as RunDetection(data). If is too large, you may want to chunk it into small pieces, and feed it to RunDetection() one by one.