Switch to shiny new fast, RLP-less trie (#795)

* Bump codec

* Fix tests

* Patricia trie builds

* Introduce trie

* Some yak shaving.

* Some fixes

* Remove RLP ref

* Fixes

* It builds!

* Some tests fixed

* Another test fix

* Rejig more hashes

* substrate-trie::iterator_works test

* Update lock

* Polish

* Docs

* Undo incorrect "fix" for tests

* Fix nits

substrate/core/client/db/src/utils.rs

@@ -25,7 +25,7 @@ use kvdb_rocksdb::{Database, DatabaseConfig};
 
 use client;
 use codec::Decode;
-use hashdb::DBValue;
+use trie::DBValue;
 use runtime_primitives::generic::BlockId;
 use runtime_primitives::traits::{As, Block as BlockT, Header as HeaderT, Zero};
 use DatabaseSettings;