Itertools are no longer reexported from util, optimized triedb iter

ethcore/src/client/test_client.rs

@@ -20,6 +20,7 @@ use std::sync::atomic::{AtomicUsize, Ordering as AtomicOrder};
 use std::sync::Arc;
 use std::collections::{HashMap, BTreeMap};
 use std::mem;
+use itertools::Itertools;
 use rustc_hex::FromHex;
 use util::*;
 use rlp::*;