Add phases to wheel events.

Needed for apps to support overscroll on the Mac.

src/api/wayland/events.rs

@@ -1,5 +1,6 @@
 use std::collections::HashSet;
 
+use TouchPhase;
 use Event as GlutinEvent;
 use ElementState;
 use MouseButton;
@@ -98,7 +99,8 @@ pub fn translate_event(
                             WlPointerAxis::HorizontalScroll => {
                                 MouseScrollDelta::PixelDelta(0.0, amplitude as f32)
                             }
-                        }
+                        },
+                        TouchPhase::Moved
                     ), surface))
                 } else {
                     None
@@ -107,4 +109,4 @@ pub fn translate_event(
         },
         _ => None
     }
-}
+}