As of r1785, iksolverbase class takes coordinates with the manipulator
grasp frame pre-multiplied for all ik types. Before this change, the
coordinate systems were mixed and lead to confusions.
Also, a new "lookat3d" ik type was added. Lookat is a subset of ray
inverse kinematics and is used to get a particular ray to point to a
specific 3D position (ie a camera sensor to look at a specific point).
The "lookat3d" type differs from "direction3d" since it also considers
the translation of the links with respect to the target position