Mostly a bugfix release

• Pinning now works with 'Track To' and 'Locked Track' constraints in addition to 'Damped Track'

• Pinning now works properly when the the tracking constraint has a bone target

• A pinned bone will more quickly converge on its specified 'stretchines' limit now (if you were noticing the pinned bone in a chain seemed to stretch excessively before). Chains of bones still requires a 'Quality' setting of at least the number of bones in the chain to get reasonably good results, and higher values will converge even more closely on the 'correct' result.

• High spring values for wiggle bones could cause instability, now the bone will clamp to being perfectly stiff when the value gets high enough, as expected.

• There was previously code that gave improper results for wiggle bones that were inheriting scale from their parents. It seems to be behaving better now, but please let me know if issues arise.

• A user identified a case where the 'is_rendering' flag somehow didn't clear after a render stopped, which prevented the wiggle simulation from running. Workaround added where toggling or changing any values in the wiggle bone panel will clear the flag, since the user is understood to be modifying the scene.