#99 Multiple midi channels

[Dubs]

Opening a midi file with tracks that send events or play on multiple midi channels puts all notes into a single track, effectively making the midi file unusable/uneditable. Please fix this.
(you don't have to add support for it, just make the file editable.)

[M Gagnon]

This has been a todo for a long time, though there is no easy fix for this unfortunately and may require to rethink the UI. Considering that my free time is very limited at the moment, I probably won't have time to look into this soon