Snake: improve auto play and remove trails
Snake: improve auto play and remove trails

- Autoplay now biases against the last turns
- Autoplay now looks upto 2 steps left and right
- Trails removed, they turned out to be confusing

kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom,kervinck/gigatron-rom