fix #1079

* move gossip/NCP off assuming anything about its address
  * use a single socket to send and receive gossip
  * remove --addr/-a from CLIs
  * rearrange networking utility code
  * use Arc<UdpSocket> to share the Sync-safe UdpSocket among threads
  * rename TestNode to Node

TODO:

  * re-enable 127.0.0.1 as a valid address in crdt
  * change repair request/response to a similar, single socket
  * pick cloned sockets or Arc<UdpSocket> for all these (rpu uses tryclone())
  * update contact_info with network truthiness instead of what the node
      says?

src/bin/fullnode.rs

@@ -7,7 +7,7 @@ extern crate solana;
 
 use clap::{App, Arg};
 use solana::client::mk_client;
-use solana::crdt::{NodeInfo, TestNode};
+use solana::crdt::{Node, NodeInfo};
 use solana::drone::DRONE_PORT;
 use solana::fullnode::{Config, Fullnode};
 use solana::logger;
@@ -78,14 +78,14 @@ fn main() -> () {
 
     let port_range = (8100, 10000);
     let node = if let Some(_t) = matches.value_of("testnet") {
-        TestNode::new_with_external_ip(
+        Node::new_with_external_ip(
             leader_pubkey,
             repl_data.contact_info.ncp.ip(),
             port_range,
             0,
         )
     } else {
-        TestNode::new_with_external_ip(
+        Node::new_with_external_ip(
             leader_pubkey,
             repl_data.contact_info.ncp.ip(),
             port_range,