[NbtkExpander] Make the expander label a property
[NbtkExpander] Make the expander label a property

jonnylamb/mx,clutter-project/mx,jonnylamb/mx,jonnylamb/mx,jonnylamb/mx,pwithnall/mx,pwithnall/mx,pwithnall/mx,pwithnall/mx,clutter-project/mx,clutter-project/mx,clutter-project/mx