#13 Hidden tracks are also muted

[JAZ]

SO:ubuntu
Midi Sheet Music 2.4

Steps to reproduce:
1)Open a multitrack midi.
2)Track->Select Tracks to display and unmark a track. The track hides prom the music sheed.
3)Verify that the track is unmuted under Track->Select Tracks to mute and that has an instrument asigned under tracks-> choose instrument.
4)Press Play.

Result obtained:
The hidden track doesn't sound

Result expected:
The hidden track to sound.

Why?:
When using 4 or more tracks in poly instrument midis you can't follow the the track you are interested in.

Possible solution:
Add a third "mute and hide" option if the original behaviour was intended.