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

[Andrei Kholodnyi]

> If you check the code, you will see that the audio library is only used
> in the modules, and that is why I am wanting to move it into the modules
> directory.
>
> I don't understand why you feel that this patch is so much more
> significant than the bigger reorganization patches we have in the
> tree.

reorganization we have made already existed in opentts.
This patch introduces "new" changes w.r.t opentts.
I just want to make sure everyone is fine with it.