API: Add debug messages to IDirectFBDisplayLayer.
API: Add debug messages to IDirectFBDisplayLayer.

Signed-off-by: Denis Oliver Kropp <3fa78fd63dd76ba74a102cf4e1e79303ef9149a1@directfb.org>

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