[Openal] lip sync

[Ryan C. Gordon]

> No, there isn't an API way.  (But you can work this out at any given
> moment based on the amount of time elapsed since you started the
> buffer playing, of course.)

Chop the data up into smaller buffers and use the queueing mechanism; 
checking for expired buffers should give you a fairly accurate idea of 
where you are in the playback if all the buffers are the same size.

--ryan.