Removed unused variable in QWaylandSurfaceNode

Change-Id: Ic140ef50c1dcef3015061d281b4d666760df167f
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
Add a size to the QWaylandServerBuffer on the client side

Change-Id: I48b7d514c1231eb4bd4a30f1329a89515b497269
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
Update the Compositor side ServerBufferIntegration

so its possible to ask for supported formats and make the
createServerBuffer function pure virtual

Change-Id: Idf07b993ea54927a51d43ef5e3a11fa1639dc1fe
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>