Correctly format ipv6 address with ports. This will also make it more compatible
with the new parse_wireaddr, which has been updated to parse ports. They are
inverses now.
Also add some tests that check this.
Signed-off-by: William Casarin <jb55@jb55.com>
We don't use it yet, but now we'll decode correctly.
See: https://github.com/lightningnetwork/lightning-rfc/pull/317
lightning-rfc commit: ef053c09431442697ab46e83f9d3f86e3510a18e
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>