A server that creates a LeafNode connection to a remote cluster
will now be notified of all possible LeafNode URLs in that cluster.
The list is updated when nodes in the cluster come and go.
Also support for advertise address, similar to cluster, gateway, etc..
Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
What is not completed:
1. TLS
2. config to bind local account.
3. Info updates for solicitor to track topology changes like a client.
4. CONNECT sent after INFO for nonce authroization.
5. Authorization
6. Services and Streams tests.
7. config file parsing.
Signed-off-by: Derek Collison <derek@nats.io>
