pay: split into getroute and sendpay

This is less convenient to use, but makes far more sense for a real
user (like a wallet).  It can ask about the route, then decide whether
to use it or not.

This will make even more sense once we add a parameter to control how
long we let the HTLC be delayed for, so a client can query for high,
medium and low tolerances and compare results.

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

daemon/jsonrpc.c

@@ -290,7 +290,8 @@ static const struct json_command *cmdlist[] = {
 	&close_command,
 	&newaddr_command,
 	&accept_payment_command,
-	&pay_command,
+	&getroute_command,
+	&sendpay_command,
 	&feerate_command,
 	/* Developer/debugging options. */
 	&echo_command,