Rename generate to pettycoin-generate.

That's the default --generate arg anyway.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Handle duplicate peers (eg. IPv4 and IPv6).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tools for making and serving seed addresses.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove serve_addresses (we can use inetd for now), rename mkaddr.

Have it spit out all the addressess as a PROTOCOL_PKT_PEER we can simply
serve.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Don't rely on server when in developer-test mode; read file directly.

And unify handling of protocol_pkt_peer.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>