gtk+.vsprops: Update for GTK-3.0
gtk+.vsprops: Update for GTK-3.0

-removed headers that ceased to exist
-bump API version
-made up for new headers that is to be installed
-gtk-demo program and related sources/data copied to bin/gtk3-demo

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