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

ethcore/src/client/config.rs

@@ -20,7 +20,8 @@ use std::fmt::{Display, Formatter, Error as FmtError};
 
 use mode::Mode as IpcMode;
 use verification::{VerifierType, QueueConfig};
-use util::{journaldb, CompactionProfile};
+use util::journaldb;
+use kvdb::CompactionProfile;
 
 pub use std::time::Duration;
 pub use blockchain::Config as BlockChainConfig;