Add code to handle both leaf styles, although it always runs the FAN style branch for now.  Will need to move the texture to be per-tree-instance (at 1024x256 pixels per, or 1 meg of bytes), before different trees can be different styles.  Plus moving it to be per-tree-instance will let the random numbers be different on different trees, giving them different leaves.  As long as they fit in video memory at a meg each...