modules: Add some error checking and assertions
modules: Add some error checking and assertions

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