Add wireframe into Workbench settings for quick and easy clay/wireframe renders

AND support for subsurf's Optimal Display, so we can also see the raw mesh on top of the final subdivised result without any wireframe cluttering:

vs

This seems like a no-brainer to add this. Wireframe renders - especially Sub-d wire frame renders are way too hard too do in Blender.

not working for me. i did the same setting in workbench