Blender Git Loki

Depsgraph: provide more granularity to PoseBone property links.

Most properties aren't altered by the evaluation of the bone,
and can be read immediately from its input operation. B-Bone
properties can be evaluated at the last possible moment.

This provides more freedom in using drivers to connect bone
properties: for example, it is now possible to read raw local
transform values via drivers from a bone that depends on the
reader bone via constraints.