Lite clear box issues

lite_clear_box is really used for clearing the parent box. This means that if you call draw_button in button.h, and use the clear flag, you tell the button to first go and find a parent's box and call its Draw function. After this the button will draw its surfaces.

If lite_clear_box does not find a parent in the parent chain with a Draw operation, it ends up in the LiteWindow's Draw function. This function will clear the whole surface of the window.

You want to do this if your LiteBox reveals the background: for instance, if you (re)move something in your LiteBox, or if you are coding an animated boundary.