The animation script used in the KF chapter is general enough
to be used by the entire book, so I removed it from the notebook
and put it in gif_animate.py
Beginning of adding animations to the chapters. I wrote the
existing material not assuming animations, so it is quite
possible that I will want to revise the chapter to better
make use of this ability. For now I just animated two different
update/predict cycles.
Chapter was not adding ../code to the search path. Multivarite discusion about the ellipses
was a bit unclear about the relationship of the standard deviation.
