Reset the mouse cursor when it leaves a toplevel window.
https://bugzilla.xamarin.com/show_bug.cgi?id=13579
https://bugzilla.gnome.org/show_bug.cgi?id=692548
Merge pull request #2 from bratsche/reset-quartz-cursor

Reset the mouse cursor when it leaves a toplevel window.
Check gdk_event_get_scroll_deltas() when scrolling menus. This fixes
unusual scrolling behavior on Mac when using trackpad or magic mouse
smooth scrolling on large popup menus.

Fixes https://bugzilla.xamarin.com/show_bug.cgi?id=13827
Merge pull request #4 from bratsche/menu-scrolling

Check gdk_event_get_scroll_deltas() when scrolling menus.