[PATCH 2/2] move src/audio to src/modules/audio

[Andrei Kholodnyi]

> The split that makes sense, I think, in the current state,
> is between the libraries that are needed or helpful in
> creating a module, and the modules themselves.

> So another structure that makes sense would be I think:

>   src/modules/common (module_utils.c etc.)
>   src/modules/common/audio (spd_audio.c etc.)
>   src/modules/festival
>   src/modules/espeak
>   etc.

I'd rather put audio under
src/modules/audio - by that means it is also clear that audio is a
common module.