## Enable debug rendering
-Setting DALI_DEBUG_RENDERING environment variable will enable the visual debugging.
+Setting DALI_DEBUG_RENDERING environment variable will enable the visual debuging.
Then, every concrete visual ( ColorVisual, BorderVisual, ImageVisual, GradientVisual, etc. ) is replaced with a DebugVisual object.
Debug visual renders a simple quad wireframe, so that the control layout and scene structure is clearly displayed.