Chopped releasing time while playing some instruments

[Wohlstand]

On example of Bank 14 (Doom 2), playing this song D_E1M4.mus.zip pay attention on a bass: in original game, it gives a bit longer release delay. However, in libADLMIDI it sounds much sorter. After a small research, I see that the reason of bug is a zero releasing delay was been detected.

I have two solutions:
Perfect:

• When instrument has a non-zero KSL, check a lower note, and scale the releasing time in dependence from a playing note
  Simple:
• For notes with a non-zero KSL, do the measure on lower notes for a fair middle result to keep release being not chopped.

[Wohlstand]

Fixed.