actor: Do not use ::constructed
actor: Do not use ::constructed

If we want to set a default layout manager, we need to do so inside
init(), as it's not guaranteed that people subclassing Actor and
overriding ::constructed will actually chain up as they should.

ebassi/clutter,djdeath/clutter-multithreaded,heysion/clutter-clone,djdeath/clutter,jigpu/clutter,djdeath/clutter,Distrotech/clutter,djdeath/clutter-android,collects/clutter,heysion/clutter-clone,GNOME/clutter,djdeath/clutter,kerrickstaley/clutter-vala,djdeath/clutter-multithreaded,GNOME/clutter,jigpu/clutter,kerrickstaley/clutter-vala,GNOME/clutter,collects/clutter,ebassi/clutter,djdeath/clutter-android,GNOME/clutter,jigpu/clutter,djdeath/clutter-multithreaded,GNOME/clutter,djdeath/clutter-android,heysion/clutter-clone,heysion/clutter-clone,djdeath/clutter,jigpu/clutter,Distrotech/clutter,kerrickstaley/clutter-vala,jigpu/clutter,djdeath/clutter-android,heysion/clutter-clone,collects/clutter,ebassi/clutter,kerrickstaley/clutter-vala,collects/clutter,ebassi/clutter,collects/clutter,Distrotech/clutter,djdeath/clutter,jigpu/clutter,ebassi/clutter,djdeath/clutter-android,Distrotech/clutter,djdeath/clutter,Distrotech/clutter,Distrotech/clutter,djdeath/clutter-multithreaded