Brute-force closest enclosers and corresponding wildcard records

[wander]

When attacking the NSEC3 hashes of a zone, make sure to try all possible closest enclosers and their corresponding wildcard records.

See ​http://tools.ietf.org/html/rfc5155#section-7.2 and Section 8.

Also: for short names up to 5 characters, attempt to brute-force all characters 0x00 to 0xFF? Might reveal whether anyone uses unusual characters. See also #16.

Depends on #5