Introduces the capability to configure TLS differently for Consul's
listeners/ports (i.e. HTTPS, gRPC, and the internal multiplexed RPC
port) which is useful in scenarios where you may want the HTTPS or
gRPC interfaces to present a certificate signed by a well-known/public
CA, rather than the certificate used for internal communication which
must have a SAN in the form `server.<dc>.consul`.
Dan Upton