Blender Git Loki

Repeat the curve smoothing pass when clamping handles.

When non-extreme Auto Clamped handles are clamped to prevent
overshoot, it creates a discontinuity with the preceeding part
of the curve that was computed under assumption of no clamping.
Thus to avoid jumps in certain situations it is necessary to
lock these handles and run the smoothing pass again.

Handles are locked in this way only if they are clamped in the
right direction; points that are trying to move against the curve
are clamped to horizontal but left free to be modified by the
subsequent pass.