Apply some lessons from the templating blogs

 - Prefer . inside ranges rather than assigning the elements to $vars
 - Use a map[string]bool instead of a func(string)bool
Use 302 Found for form redirects
Add "view game" page
Clean up template a bit, using more blog trickery

May as well use Range's short names.
Finish index page

This involved fixing the database schema a bit. But because NO ONE is
using this project, I just edited migration 0002. TAKE THAT, SANITY.

CATS AND DOGS.

YOU KNOW THE DEAL.