RetroPlayerAudio - Greatly improved audio tracking for video.

Previously, it was typically 0.15% off. Now I'm seeing the same speed for both tracks to the limits of my brief testing.

Audio delay is still present. It can be mitigated by:

```xml
<advancedsettings>
    <games>
        <audiobuffer>500</audiobuffer> <!-- Audio delay (ms), lower = underruns -->
    </games>
</advancedsettings>
```