Merged requested to merge p12tic/pygobject:gdk-overrides-scroll-event into master
Gdk.EventType.SCROLL events have not been properly wrapped, as e.g.
event.direction = XYZ does not modify the underlying event. The actual event object lives in
event.scroll subobject. All other event types implement attribute access passthrough to that object, so perhaps we should do the same for scroll events.