builder: automatically add new widgets to a parent container
builder: automatically add new widgets to a parent container

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