[AD] API review: audio events

[Peter Wang <novalazy@xxxxxxxxxx>]

Hi,

The aqueue driver is the only one which emits these new events.

    ALLEGRO_EVENT_AUDIO_ROUTE_CHANGE
    ALLEGRO_EVENT_AUDIO_INTERRUPTION
    ALLEGRO_EVENT_AUDIO_END_INTERRUPTION

I think the events can and should be generated by the driver's solitary
voice instead of a new special purpose audio event source.

So how about:

    ALLEGRO_EVENT_AUDIO_INTERRUPTION -> ALLEGRO_EVENT_VOICE_STOPPED
    ALLEGRO_EVENT_AUDIO_END_INTERRUPTION -> ALLEGRO_EVENT_VOICE_STARTED
    ALLEGRO_EVENT_ROUTE_CHANGE -> ALLEGRO_EVENT_VOICE_ROUTE_CHANGE
    al_get_audio_event_source -> al_get_voice_event_source

Not sure what a program would do upon knowing that the route changed,
though.  It's supposed to be transparent anyway, isn't it?

Peter