Services v2 (ip-per-service)

DO NOT COMMIT.  Needs test updates and a new e2e test.  Some FIXMEs still.  95% complete.

Add support for IP-per-service behavior.  This creates virtual IP addresses for each service, and uses iptables to route traffic "magically".

The first few commits are relatively independent, and could be extracted to different PRs, if you feel like making me suffer.

See #1107 for background.
We run iptables in a loop.  Logging an error message, when it isn't an error, will cause log bloat and more importantly consternation from anyone who reads the log and wonders why it is getting an error.  I know because it bothered me enough to fix this.

Sadly, that is the iptables interface :(