connectd: always tell master when connection fails/succeeded.

We used to separate implicit connection requests (ie. timed retries
for important peers) and explicit ones, and send a
WIRE_CONNECTCTL_CONNECT_TO_PEER_RESULT for the latter.

In the success case, that's now redundant, since we hand the connected
peer to the master using WIRE_CONNECT_PEER_CONNECTED; we just need a
message for the failure case.  And we might as well tell the master
every failure, so we don't have to distinguish internally.

This also solves a race we had before: connectd would send
WIRE_CONNECTCTL_CONNECT_TO_PEER_RESULT which completes the incoming
JSON connect command, then send WIRE_CONNECT_PEER_CONNECTED.  So
there's a window where the JSON command can return, but the peer isn't
known to lightningd yet.

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

lightningd/connect_control.h

@@ -9,6 +9,7 @@ struct pubkey;
 int connectd_init(struct lightningd *ld);
 void connectd_activate(struct lightningd *ld);
 
+void connect_succeeded(struct lightningd *ld, const struct pubkey *id);
 void gossip_connect_result(struct lightningd *ld, const u8 *msg);
 
 #endif /* LIGHTNING_LIGHTNINGD_CONNECT_CONTROL_H */