Separate migrations from util (#6690)

* separate migration from util and make its dependencies into libs:

* snappy
* kvdb
* error
* common

* renamed common -> macros

* util error does not depend on snappy module

* ethsync does not depend on util nor ethcore_error

* nibbleslice and nibblevec merged with patricia_trie crate

* removed unused dependencies from util

* util journaldb traits does not need to be public

* util_error

* fixed ethcore compile error

* ignore .swo files

* Update chain.rs

sync/src/chain.rs

@@ -14,7 +14,6 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-///
 /// `BlockChain` synchronization strategy.
 /// Syncs to peers and keeps up to date.
 /// This implementation uses ethereum protocol v63
@@ -2230,19 +2229,18 @@ fn accepts_service_transaction(client_id: &str) -> bool {
 #[cfg(test)]
 mod tests {
 	use std::collections::{HashSet, VecDeque};
+	use {ethkey, Address};
 	use network::PeerId;
 	use tests::helpers::*;
 	use tests::snapshot::TestSnapshotService;
 	use bigint::prelude::U256;
 	use bigint::hash::H256;
-	use util::Address;
 	use parking_lot::RwLock;
 	use bytes::Bytes;
 	use rlp::{Rlp, RlpStream, UntrustedRlp};
 	use super::*;
 	use ::SyncConfig;
 	use super::{PeerInfo, PeerAsking};
-	use ethkey;
 	use ethcore::header::*;
 	use ethcore::client::{BlockChainClient, EachBlockWith, TestBlockChainClient};
 	use ethcore::transaction::UnverifiedTransaction;