wayland: Use on globals closure for loading cursor themes
wayland: Use on globals closure for loading cursor themes

Instead of putting a 'load cursor themes' call when receiving an wl_shm
global, make it a closure that is prepared during initialization.

https://bugzilla.gnome.org/show_bug.cgi?id=719819

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