Blender Git Loki

UI: support jumping to target object/bone

Complex rigs are built from many bones (often overlapping)
connected by constraints.

When investigating or debugging such rigs one often wants to switch to
the target of a constraint, or a parent bone, but it is difficult to do
manually due to overlap confusion.

This adds a right click menu option that automatically selects
and makes the target object or bone active for UI fields where a
suitable reference is readily available.