multi host client demo

Bind to the same interface as the user supplied client address.

src/accountant_stub.rs

@@ -41,6 +41,7 @@ impl AccountantStub {
         let subscriptions = vec![Subscription::EntryInfo];
         let req = Request::Subscribe { subscriptions };
         let data = serialize(&req).expect("serialize Subscribe");
+        trace!("subscribing to {}", self.addr);
         let _res = self.socket.send_to(&data, &self.addr);
     }
 
@@ -114,6 +115,7 @@ impl AccountantStub {
     pub fn get_last_id(&mut self) -> FutureResult<Hash, ()> {
         let req = Request::GetLastId;
         let data = serialize(&req).expect("serialize GetId");
+        assert!(data.len() < 4096);
         self.socket
             .send_to(&data, &self.addr)
             .expect("buffer error");