Improves device selection via portaudio for MacOSX (hostapi coreaudio): adds...

Improves device selection via portaudio for MacOSX (hostapi coreaudio): adds the possibility to get the device transport type (USB, bluetooth, etc.) and an unique identifier. Corrects problems when: loading the same device twice (for the moment only for the same hostapi), a new plugged device is selected during a call or if the selected device is unchanged.