Blender Git Loki

Sculpt: New "auto-fset" setting

Added a new "auto face set" setting for brushes.
It basically invokes the draw face set tool,
with a few differences:

* The painted face set is fixed by user setting.
* More then one face set can be created,
these are assigned based on distance to
the stroke line.
* TODO: write a proper API for wrangling stroke
curves (should interpolate at least G2!).

The point of this is to enable better hard surface
brushes. Since the settings are extremely finicky
I've added an example of one (based on clay strips)
to startup.blend.

The necassary steps to make a hard brush out of this
are as follows:

1. Autosmooth: ~0.4;
2. Autosmooth radius scale: ~1.5.
3. Auto fset: on.
4. Hard edge mode: on (but turn off inherit).