basics of animated version working

no speed control and some not so good transitions, but getting there
working with basic speed control

Works with smooth animations.  Basic speed control, which is okay up to
about 4x speed.  Need to work in generation skipping.
still better

changes to js, css and index.html.  Works a bit better
almost there

each generation produces 2400 seeds, and most phrases can be evolved in
under 50 generations.   Still needs some work on buttons and the 'how
this works' button in particular, and the code needs to be cleaned up.