Replace the Google map on the IP address show page with a Bing map. Bing
doesn't require an API key, which makes it easier to deploy. The Google
Maps API requires to you to whitelist the IP addresses and domains you
plan to use with your API key, which is inconvenient for development
because it means maps won't display unless you whitelist your
development IPs.
* Make IP bans soft deletable.
* Add a hit counter to track how many times an IP ban has blocked someone.
* Add a last hit timestamp to track when the IP ban last blocked someone.
* Add a new type of IP ban, the signup ban. Signup bans restrict new
signups from editing anything until they've verified their email
address.
