Implements an alternative to PortAudio on Windows which uses Windows Audio Session API (WASAPI) and related Core Audio APIs such as Multimedia Device (MMDevice) API.

Creates a dedicated thread for changing on-going call volume. Uses the system volume to update the volume slider when the slider becomes visible.

Corrects UnsatisfiedLinkError when trying to load nonexistent Windows or MacOSX CoreAudio library. Initializes microphone volume based on system value for MacOSX and Windows Vista/7/8.

Work in progress using Windows CoreAudio API to set the input device volume (hardware microphone sensibility).

- Fixes spelling mistakes.
- Fixes warnings.