Core: Add ToString<DFBRectangle>
Core: Add ToString<DFBRectangle>

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