separate trie from util and make its dependencies into libs:

* bytes
* hashdb
* memorydb
* nibbleslice
* nibblevec

dapps/src/tests/helpers/registrar.rs

@@ -21,7 +21,8 @@ use rustc_hex::FromHex;
 
 use hash_fetch::urlhint::ContractClient;
 use bigint::hash::H256;
-use util::{Bytes, Address, ToPretty};
+use util::Address;
+use bytes::{Bytes, ToPretty};
 use parking_lot::Mutex;
 
 const REGISTRAR: &'static str = "8e4e9b13d4b45cb0befc93c3061b1408f67316b2";