New `<twisty-player>` features

[lgarron]

After #130:

• [x] Dynamic display options in PG3D #121
• [ ] experimentalFoundation
• [x] Reusing renderers by default.
• [ ] Avoid Safari fullscreen letterboxing on iPad
• [x] Autoplay & looping / animation direction
• [x] Picture puzzles
• [ ] Skip to the next move each additional time "step forward" is pressed.