wayland: Allow placing subsurfaces below parent surfaces
According to the spec, if the wl_subsurface.place_below request is called with the parent surface, the sub-surface must be placed below the parent surface.
Edited by Vlad Zahorodnii
According to the spec, if the wl_subsurface.place_below request is called with the parent surface, the sub-surface must be placed below the parent surface.