widget: make sure ensure_style is recursive if the widget is a container
widget: make sure ensure_style is recursive if the widget is a container

Emmitting style-changed will not recurse to the children if the actor is
not mapped.

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