force sending of mouse button release on xwl drag end
force sending of mouse button release on xwl drag end

seems to be necessary for the client to end its drag

tasn/enlightenment,rvandegrift/e,rvandegrift/e,tasn/enlightenment,tizenorg/platform.upstream.enlightenment,tasn/enlightenment,tizenorg/platform.upstream.enlightenment,tizenorg/platform.upstream.enlightenment,rvandegrift/e