Fix QWaylandSurfaceItem to process hover events

setAcceptHoverEvents was set to true but the methods
to handle it werern't implemented

Change-Id: I53719b00eac27b3b903a882fd2aa91fd6a51973e
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
Fix popup positioning

The popup coordinates were being stored in an
unused variable and x,y offsets were left unmodified

Change-Id: Idbae7127b65963be6ddbe165d98ac7daa92cac9f
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
Reviewed-by: Giulio Camuffo <giulio.camuffo@jollamobile.com>