Build "sponge" node for abuse

[jfesler]

We're seeing the occasional case where a heavy amount of abuse comes from one particular source (Whether by IP, or ISP, or country). It would be nice to have a place to send that traffic that's distinct from the normal production load, that can soak up the traffic, and I/O, that said abuse causes.

• [x] Build vm0.test-ipv6.com
• [x] Validate vm0.test-ipv6.com
• [x] Update GSLB configs to support vm0.test-ipv6.com as a serving platform
• [x] Identify candidate ISPs based on current attack patterns
• [x] Update the GSLB configs to use vm0.test-ipv6.com for those ISPs

This won't catch the case where users are using Google Public DNS (and similar); but it will still hopefully reroute the bulk of the abuse.

[jfesler]

New VM is now taking the traffic for IR and CN; at least for clients using DNS resolvers located in IR and CN.