Blender Git Loki

Improve Solidify/Bevel Modifier cooperation

Adds a slider to solidify which allows the user to add bevel weight on the outside
or remove bevel weight from the inside.

Also includes a very small improvment for working with subsurface modifier where
the rim edge in complex solidify will now also have a chance to get a crease if
there is only two adjacent edges.

Differential Revision: https://developer.blender.org/D7334

Reviewing and minor cleanups: Bastien Montagne (@mont29).