Upgraded cellmap.
- Added user-controllable example of air CA.
- Added automaton.js to handle applying reactions to cellmaps. (Lifted from airtests-fixtures.)
- Made airreaction.js browser-safe.
- Switched to blue air, gray inert color scheme.
- Made the jump in representation from 0 pressure to something pressure 0.25 instead of 0.5.
- Hooked up #next-button.
- Added explanation.