CutBuf3 swells in volume on rolls

[nhthn]

When the clock tempo is faster than the buffer tempo, CutBuf3 swells in volume for fast rolls:

~buf = BBCutBuffer(Platform.resourceDir +/+ "sounds/break.aiff", 8);
BBCut2(CutBuf1(~buf, 0.5), WarpCutProc1()).play(3.5); // ok
BBCut2(CutBuf2(~buf, 0.5), WarpCutProc1()).play(3.5); // ok
BBCut2(CutBuf3(~buf, 0.5), WarpCutProc1()).play(3.5); // volume increase for rolls

This behavior is logical (caused by overlapping grains where the grain duration is larger than the IOI), but unaesthetic. CutBuf3 should provide an option to cut grains short for rolls, and have it on by default.