[subwindows] Destroy all sub windows first in window destruction code.
[subwindows] Destroy all sub windows first in window destruction code.

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