Now can compute target segment tip frame's velocity with respect to ref segment and express it in target tip coordinates. Also added a method to compute target segment tip frame's pose wrt to ref segment's joint frame
refactored some functions to have consistent naming
added documentation
rearranged some parts of the code and exposed ref and target segments of the Joint class
minor changes
trying to create a segment tree from the given sequence of joints
can find number of children, now need to find who they are