Added a Quasistatic solve for the Bend/Twist constraints present in hair simulations. Although it requires updated stiffness settings from the default Dynamic method, it can provide higher bend stiffness for some simulations, particularly with branching hair.

New Angular Damping parameter on the Vellum Solver, similar to the existing Velocity Damping. It applies a brute force damping to the angular velocity present in hair simulations, causing sudden rotations to be quickly damped.