Allow minimal implementation of GtkCellLayout
Allow minimal implementation of GtkCellLayout

Since GtkCellArea delegate does all the work, cell layout widgets
who use a GtkCellArea internally only have to implement the _get_area()
method, this just reduces code to forward the calls over the the internal
cell area.

Adamovskiy/gtk,chergert/gtk,Adamovskiy/gtk,alexlarsson/gtk,davidgumberg/gtk,Adamovskiy/gtk,ebassi/gtk,davidt/gtk,davidgumberg/gtk,Distrotech/gtk2,Adamovskiy/gtk,simokivimaki/gtk,ahodesuka/gtk,grubersjoe/adwaita,jadahl/gtk,msteinert/gtk,Adamovskiy/gtk,davidgumberg/gtk,Distrotech/gtk2,alexlarsson/gtk,Sidnioulz/SandboxGtk,Distrotech/gtk2,davidt/gtk,ebassi/gtk,chergert/gtk,Sidnioulz/SandboxGtk,jadahl/gtk,davidt/gtk,grubersjoe/adwaita,Adamovskiy/gtk,msteinert/gtk,grubersjoe/adwaita,jigpu/gtk,ahodesuka/gtk,davidt/gtk,Lyude/gtk-,Distrotech/gtk2,jadahl/gtk,alexlarsson/gtk,jigpu/gtk,jigpu/gtk,simokivimaki/gtk,Distrotech/gtk2,jessevdk/gtk,Lyude/gtk-,davidgumberg/gtk,grubersjoe/adwaita,chergert/gtk,davidgumberg/gtk,jadahl/gtk,alexlarsson/gtk,simokivimaki/gtk,bratsche/gtk-,Sidnioulz/SandboxGtk,Lyude/gtk-,simokivimaki/gtk,alexlarsson/gtk,davidgumberg/gtk,ahodesuka/gtk,davidt/gtk,Sidnioulz/SandboxGtk,bratsche/gtk-,alexlarsson/gtk,simokivimaki/gtk,chergert/gtk,jessevdk/gtk,jessevdk/gtk,msteinert/gtk,davidt/gtk,jessevdk/gtk,ebassi/gtk,msteinert/gtk,jadahl/gtk,bratsche/gtk-,jadahl/gtk,jigpu/gtk,grubersjoe/adwaita,chergert/gtk,msteinert/gtk,jadahl/gtk,grubersjoe/adwaita,msteinert/gtk,Lyude/gtk-,simokivimaki/gtk,jigpu/gtk,ahodesuka/gtk,jigpu/gtk,jessevdk/gtk,Sidnioulz/SandboxGtk,chergert/gtk,jadahl/gtk,ebassi/gtk,bratsche/gtk-,grubersjoe/adwaita,bratsche/gtk-,ahodesuka/gtk,Sidnioulz/SandboxGtk,ahodesuka/gtk,ahodesuka/gtk,grubersjoe/adwaita,chergert/gtk,alexlarsson/gtk,jessevdk/gtk,Adamovskiy/gtk,davidgumberg/gtk,Distrotech/gtk2,jigpu/gtk,Adamovskiy/gtk,alexlarsson/gtk,ahodesuka/gtk,Lyude/gtk-,bratsche/gtk-,jessevdk/gtk,Lyude/gtk-,chergert/gtk,jigpu/gtk,ebassi/gtk,davidgumberg/gtk,Lyude/gtk-,Lyude/gtk-,ebassi/gtk