Target rotations are implemented and can optionally be enabled:
It's possible to change the rotation weight and decay parameters on a per-effector basis (not shown). And, like everything else, the rotations are propagated correctly over arbitrary trees.
My current TODO list is:
* - Actually implement tolerance.
* - Fix rotation issue with shared sub-base nodes -> rotations need to be
* - Add support for manually updating initial pose.
* - Script bindings.
* - Optimise.
* - Profile.
* - Documentation.
* - Support for "stretchiness" with min/max lengths.
* - Support for "stiffness" factor, describes how well a bone rotates.
* - Apply bullet constraints to joints.