Blender Git Loki

Armature: apply Y scale to B-Bone segments.

This fixes a strange behavior where the segments were not actually
scaled in the Y direction to match their actual length, thus
producing gaps or overlap depending on the shape of the curve. For
transformation the change should be very small if enough segments
are used, but this will affect the results of the Copy Transforms
and Armature constraints, so a backwards compatibility option is
provided. Newly created bones default to the new behavior.