Fix for bug that occurs if extractFeatherstone is called more than once.
PlanarRigidBodyManipulator/forwardKinV updates.
Fixed mistakes in replacing RigidBodyManipulator.featherstone.NB.
Getting rid of f_ext_map_from and f_ext_map_to. Fixed mistake in manipulatorDynamics (external wrenches). Set use_mex to false for now in doKinematics.
Got rid of a tiny bit of code duplication.
Got rid of inds in extractFeatherstone.
Cleanup.
Changed manipulatorDynamics C computation with external forces: external forces are expressed in 'joint' frame and I was transforming from body frame to world instead of from joint frame to world.