Fix bug in finding neighbour rows

Some of the modulo and values were wrong  - now fixed
Add a queen bee example

This is a shuttle/oscillator with period 30
Include Acorn example

Acorn is a Methuselah, and is stable after 5206 generations.
We only look at a small number of this as we need (with the
torodial array) to keep track of the 13 escaped gliders which
could get a long way away. If we find the right size box we can try
this.