rework of netwrk rendezvous

* rename NodeInfo field of Node from "data" to "info"
      (touches a lot of files)

  * update client to use gossip to find leader, a la drone

  * rework multinode scripts
      * move more stuff into rust
      * added usage to all
      * no more rsync unless you're a validator (TODO: whack that, too)
  * fullnode doesn't bail if drone isn't up yet, just keeps trying
  * drone doesn't bail if network isn't up yet, just keeps trying

ci/localnet-sanity.sh

@@ -70,7 +70,7 @@ echo "--- Wallet sanity"
 echo "--- Node count"
 (
   set -x
-  ./multinode-demo/client.sh "$PWD" 3 -c
+  ./multinode-demo/client.sh localhost --num-nodes 3 --converge-only
 ) || flag_error
 
 killBackgroundCommands