Internalized nAudio library.

Moved all nAudio code into the base namespace.

Removed the NAudio Folder, and moved all internal code inside the internal folder, so it's easier to see exactly what components are visible
Moved System Specific enumerator and devices into a system namespace.

Split the generic autio controller into its own code file

Moved native methods to internal folder
Merge branch 'master' of https://github.com/xenolightning/AudioSwitcher.AudioApi.git