Reset single_window to NULL when hiding the layer to have the surface buffers recreated during configuration.
Reset single_window to NULL when hiding the layer to have the
surface buffers recreated during configuration.

deniskropp/DirectFB,djbclark/directfb-core-DirectFB,djbclark/directfb-core-DirectFB,mtsekm/test,kevleyski/DirectFB-1,kaostao/directfb,deniskropp/DirectFB,DirectFB/directfb,DirectFB/directfb,dfbdok/DirectFB1,lancebaiyouview/DirectFB,djbclark/directfb-core-DirectFB,mtsekm/test,djbclark/directfb-core-DirectFB,jcdubois/DirectFB,kevleyski/directfb,sklnet/DirectFB,mtsekm/test,kaostao/directfb,sklnet/DirectFB,lancebaiyouview/DirectFB,sklnet/DirectFB,DirectFB/directfb,kevleyski/DirectFB-1,deniskropp/DirectFB,kevleyski/directfb,kevleyski/DirectFB-1,kaostao/directfb,dfbdok/DirectFB1,lancebaiyouview/DirectFB,dfbdok/DirectFB1,jcdubois/DirectFB,lancebaiyouview/DirectFB,jcdubois/DirectFB,deniskropp/DirectFB,kevleyski/directfb,Distrotech/DirectFB,kevleyski/directfb,Distrotech/DirectFB,kevleyski/DirectFB-1,sklnet/DirectFB,Distrotech/DirectFB