box-layout: Use allocate_align_fill()
box-layout: Use allocate_align_fill()

Remove duplicated code, and use the newly added actor method to compute
the child allocation based on alignment and fill.

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