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-config.rs

@@ -5,9 +5,9 @@ extern crate serde_json;
 extern crate solana;
 
 use clap::{App, Arg};
-use solana::crdt::{get_ip_addr, parse_port_or_addr};
+use solana::crdt::GOSSIP_PORT_RANGE;
 use solana::fullnode::Config;
-use solana::nat::get_public_ip_addr;
+use solana::nat::{get_ip_addr, get_public_ip_addr, parse_port_or_addr};
 use solana::signature::read_pkcs8;
 use std::io;
 use std::net::SocketAddr;
@@ -48,13 +48,7 @@ fn main() {
         .get_matches();
 
     let bind_addr: SocketAddr = {
-        let mut bind_addr = parse_port_or_addr({
-            if let Some(b) = matches.value_of("bind") {
-                Some(b.to_string())
-            } else {
-                None
-            }
-        });
+        let mut bind_addr = parse_port_or_addr(matches.value_of("bind"), GOSSIP_PORT_RANGE.0);
         if matches.is_present("local") {
             let ip = get_ip_addr().unwrap();
             bind_addr.set_ip(ip);