Comment 17 for bug 976650

I've adapted Owen's patch from #10 to fix the case where the user has waveforms generated from trunk or a previous 1.11.0 alpha release.

Now that we're max()'ing across the strides, I'm not sure that a pow(..., 0.316) is necessary. For me, the pow() caused the waveform to be somewhat muddled while I think the max() alone looks pretty good.

I also removed the factor of 0.5 from the replaygain in EnginePregain. Not sure why that was there (maybe Vittorio will comment).