wish: post-AU peak level/volume normalization

In order to make the most of DAC bit depth, it would be helpful if A+ could normalize the peak level/volume of tracks after they are processed by AU plugins. This would be analogous to the ReplayGain feature, but applied after plugins. For context, I use a couple plugins (e.g. room correction) that result in a significant level reduction to protect against clipping. It would be useful if A+ could raise these levels on a case-by-case basis so that clipping could still be avoided. The best solution might be to normalize the volume following the current approach used for ReplayGain, but protect against clipping, leaving a track quieter if clipping would occur. I would be perfectly happy if this play mode required a setting allowing buffers to be grown to hold a full track, and if playback did not start until after the entire track was loaded into memory and processed.