Blender Git Loki

Fix T41147: Static BVH shading problem
Fix T41079: Solid black render of object with negative scale and smooth shading

In both cases the issue was caused by negative scaled objects with single mesh
users for which scale gets applied when using static BVH.

Since the on-fly normals calculation land normals for such cases weren't flipped
leading them to point to a wrong direction.

Added a special object flag for this, which is a bit of a bummer because now
we've got less bits for real useful things, but this is the only way to get
proper normals without adding more complexity in the on-fly calculations.