net: flesh out LookupPort static services for nacl, etc

[bradfitz]

Note that this program,

https://play.golang.org/p/zBvrVFM6M7

func port(name string) {
    num, err := net.LookupPort("tcp", name)
    log.Printf("Port(%q) = %v, %v", name, num, err)
}

func main() {
    port("http")
    port("https")
    port("ftp")
    port("ssh")
}

Prints this on the playground:

2009/11/10 23:00:00 Port("http") = 0, Protocol not available
2009/11/10 23:00:00 Port("https") = 0, Protocol not available
2009/11/10 23:00:00 Port("ftp") = 0, Protocol not available
2009/11/10 23:00:00 Port("ssh") = 0, Protocol not available

We should probably bake in a more complete /etc/services for nacl and other places without /etc/services on their filesystem.

The list is small and changes very infrequently.

/cc @ianlancetaylor @mikioh

[gopherbot]

CL https://golang.org/cl/28951 mentions this issue.