macos/windows/linux build using cc crate

[SergejJurecko]

This may simply serve as an example how to build portaudio using the cc crate. I added the portaudio sources from latest release directly in the project. I don't know how others feel about that, but it is by far the most convenient and safest way.

macOS and Windows (msvc) builds work well. I have not tested on linux yet.

[xasopheno]

This works for me on Windows. Really cool. Thank you.