Ensure that we're reusing the base configuration between client and
servers without the possibility of drift. Reduce the amount of `sed`
mangling of the configuration file, and make recommended changes from
`shellcheck` for this section of the provisioning script.
Fixes some rebase errors on the Nomad config as well.
Update the Consul and Vault configs to take advantage of their
included `go-sockaddr` library for getting the IP addresses we need in
a portable way. This particularly avoids problems with "predictable"
interface names provided by systemd.
Also adds the `sockaddr` binary to the Packer build so we can use it
in our provisioning scripts.
Tim Gross