Internally the dns code has the ability to try connecting to multiple
addresses in a sequence. Expose this, as we'll want it for reconnection.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Also based on pettycoin code.
(With embarrassing bug fixed where it didn't increment the address used,
thus using 100% CPU if that connect failed!)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>