Amend deprecation warnings for GtkStyle API
Amend deprecation warnings for GtkStyle API

Not everything has a replacement in the API, as the drawing model
changed considerably; nevertheless, this should help out developers
porting from the deprecated GtkStyle API.

jigpu/gtk,grubersjoe/adwaita,chergert/gtk,davidgumberg/gtk,jadahl/gtk,grubersjoe/adwaita,chergert/gtk,Adamovskiy/gtk,grubersjoe/adwaita,chergert/gtk,jigpu/gtk,davidgumberg/gtk,grubersjoe/adwaita,Adamovskiy/gtk,Adamovskiy/gtk,jadahl/gtk,jadahl/gtk,grubersjoe/adwaita,chergert/gtk,jadahl/gtk,grubersjoe/adwaita,jigpu/gtk,jigpu/gtk,jadahl/gtk,Adamovskiy/gtk,jadahl/gtk,jigpu/gtk,jadahl/gtk,jadahl/gtk,chergert/gtk,jigpu/gtk,grubersjoe/adwaita,davidgumberg/gtk,alexlarsson/gtk,Adamovskiy/gtk,alexlarsson/gtk,jigpu/gtk,davidgumberg/gtk,jigpu/gtk,alexlarsson/gtk,davidgumberg/gtk,Adamovskiy/gtk,alexlarsson/gtk,Adamovskiy/gtk,alexlarsson/gtk,Adamovskiy/gtk,alexlarsson/gtk,davidgumberg/gtk,chergert/gtk,davidgumberg/gtk,davidgumberg/gtk,grubersjoe/adwaita,chergert/gtk,alexlarsson/gtk,chergert/gtk,alexlarsson/gtk