gdk: deal with GDK_SMOOTH_SCROLL events as not having a direction
gdk: deal with GDK_SMOOTH_SCROLL events as not having a direction

gdk_event_get_scroll_direction() will return FALSE on these, so
gdk_event_get_scroll_deltas() has to be used to retrieve dx/dy

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