Refactors references to MemoryLruCache in ethcore (#6693)

ethcore/src/engines/validator_set/safe_contract.rs

@@ -27,7 +27,7 @@ use parking_lot::{Mutex, RwLock};
 
 use util::*;
 use bytes::Bytes;
-use util::cache::MemoryLruCache;
+use memory_cache::MemoryLruCache;
 use unexpected::Mismatch;
 use rlp::{UntrustedRlp, RlpStream};
 

ethcore/src/lib.rs

@@ -129,6 +129,7 @@ extern crate bloomable;
 extern crate vm;
 extern crate wasm;
 extern crate ethcore_util as util;
+extern crate memory_cache;
 
 #[macro_use]
 extern crate macros;

ethcore/src/state_db.rs

@@ -17,7 +17,7 @@
 use std::collections::{VecDeque, HashSet};
 use std::sync::Arc;
 use lru_cache::LruCache;
-use util::cache::MemoryLruCache;
+use memory_cache::MemoryLruCache;
 use util::journaldb::JournalDB;
 use kvdb::{KeyValueDB, DBTransaction};
 use bigint::hash::H256;