Usually, if mouse events are equal to (0, 0) we filter them out.
However, if the event is very close to zero it will still be given to
the user. In some cases this can be caused by bad float math on the X11
server side.
Fix it by filtering absolute values smaller than floating point epsilon.
Signed-off-by: John Nunley <dev@notgull.net>
Closes: #3500
