Blender Git Loki

Sculpt: Cloth Snake Hook Brush

This implements Snake Hook as a deform type for the cloth brush. This
brush changes the strength of the deformation constraints per brush step
to avoid affecting the results of the simulation as much as possible. It
allows to grab the cloth without producing any artifacts in the surface
and create more natural looking folds than any of the other deformation
modes.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D8621