Fixed multiple free during destruction of the window stack (grabbed keys).
Fixed multiple free during destruction of the window stack (grabbed keys).

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