Save track height under a separate name, 'trackheight'

[zonkmachine]

Temporary fix for #3721.

[zonkmachine]

@PhysSong Merge?

[PhysSong]

It should work without compatibility problem, but I want to know how @michaelgregorius thinks.

[michaelgregorius]

So if I understand correctly then files stored with this patch will differentiate between trackheight which stores the height of the track as shown in the Song Editor and height which stores the height of the instrument window. Therefore loading and saving of such new files will work without the two classes interfering with each other. If an old file is loaded the new attribute trackheight will not be found and in these cases the tracks will be restored to their default height. Is this correct? If that's the case then the patch looks good to me.

@zonkmachine, @PhysSong: Thanks for working on this issue!

[zonkmachine]

Is this correct?

Correct. I've tested this and it fixes the issue. Merge?

[michaelgregorius]

@zonkmachine I'd say let's merge this.

[zonkmachine]

🚜