By default NSWindow does not listen to mousemoved events and hence the
default behaviour for Actors using the "motion-event" signal differs
from backend to backend.
Using setAcceptsMouseMovedEvents seems to fix it; unfortunately, I
cannot verify it, but since nobody is currently working on the Quartz
backend I guess it cannot get more broken than how currently is.
Thanks to: Michael <michael@f3k.org>
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1687
7a8895944b