Previously we let the user use the audio device ID, but this is not persistent
and can change when plugging in new devices. That of course made it quite
worthless for storing it as a user setting for GUIs, or for user scripts.
In theory getting the kAudioDevicePropertyDeviceUID can fail but it doesn't
on any of my devices, so I'm leaving the error reporting quite high and see if
someone complains.
Introduce some macros to deal with properties. These allow to work around the
limitation of CoreAudio's API being `void **` based. The macros allow to keep
their client's code DRY, by not asking size and other details which can be
derived by the macro itself. I have no idea why Apple didn't design their API
like this in the first place.
* ao_coreaudio_utils: contains several utility function
* ao_coreaudio_properties: contains functions to set and get audio object
properties.
Conflicts:
audio/out/ao_coreaudio.c
Stefano Pigozzi