disc grouping

[ochosi]

i ran into the problem of grouping discs in my songtree layout (previously used simple title for that), so i quickly edited the existing songtree groupings to get this (see screenshot):

{Group discleft}
title=disc on the left side
left=width
title:   text(markup='<b><big>'.pesc($title).'</big></b>',pad=2,w=left)
width:   OptionNumber(default=15,min=10,max=100,step=1)

enjoy!