bootstrap a first noteOff (not yet working in the tracker)
begin release, temporary noteOff for the tracker, noteOff for MIDI
add decay back
decayVolume
Implementing the noteOff & add 'off' on the tracker
add sustain property
Fix module change property bug
also record the noteOff to put on the tracker
Bugfix releaseHoldingNotes
Merge pull request #19 from gre/noteOff

Add "hold a note" feature