Blender Git Loki

Cycles: Fix shading with autosmooth and custom normals

New logic of split_faces was leaving mesh in a proper state
from Blender's point of view, but Cycles wanted loop normals
to be "flushed" to vertex normals.

Now we do such a flush from Cycles side again, so we don't
leave bad meshes behind.

Thanks Bastien for assistance here!