twists work now, just need to correct semantics for each available twist and use them to compute forward velocity twist kinematics
corrected twist composition required to compute forward  twist kinematics. The values of the coordinate computations seem to be wrong. Need to check whether the correct reference point and coord frame is being used
the position vector used in changePoint method of twist has inverted interpretation than the one in kdl. That is why -1 product is used. But this need to be replaced by using existing method of Position primitive. Such as Position.changePoint and Position.changeCoordinate.
The values are correct so I can start building accTwists and Wrenches. Also maybe should perform all of the in the loop, this would greatly simplify the code.
computation of twist, acctwist using their public methods (changepoint, composition etc) works. Need to document the process how it is done.
Next to be done is wrench  operations
minor corrections console printouts
compact version works, just need to do more tests
everything works fine now. Next is to introduce wrenches