Group: Unstable (example)

This patch makes the Animation System call the "update()" callbacks associated with RNA properties, which solves many issues, particularly those related to the way that some modifiers have been wrapped.

See "[Bf-committers] RNA property updates vs anim sys" for a brief discussion of the issue.

I'm including this patch here in case anyone desperately needs this functionality working. However, as it is, I don't think it's really suitable for inclusion yet, as in a test file, I got 4x slowdowns, making animation playback with a production-grade rig completely unusable. Anyways, for better or for worse, it is here.