Blender Git Loki

Split Normals I (4/5): Add support of split normals to BI renderer.

Note that this commit completely replaces old behavior of the auto_smooth feature in BI.

Also note that split normals are only handled when no "advanced geometry post-processing" is used
(something like Displace will obviously break it, since it has to re-compute normals after displacement...).

Reviewers: brecht

Reviewed By: brecht

CC: campbellbarton

Differential Revision: https://developer.blender.org/D368