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

util/error/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "util-error"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+
+[dependencies]
+rlp = { path = "../rlp" }
+ethcore-bigint = { path = "../bigint" }
+error-chain = "0.11.0-rc.2"
+rustc-hex = "1.0"

util/error/src/lib.rs

@@ -0,0 +1,72 @@
+// Copyright 2015-2017 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! General error types for use in ethcore.
+
+#![allow(missing_docs)]
+#![allow(unknown_lints)]
+
+#[macro_use]
+extern crate error_chain;
+
+extern crate ethcore_bigint as bigint;
+extern crate rlp;
+extern crate rustc_hex;
+
+use std::fmt;
+use rustc_hex::FromHexError;
+use rlp::DecoderError;
+use bigint::hash::H256;
+
+#[derive(Debug)]
+/// Error in database subsystem.
+pub enum BaseDataError {
+	/// An entry was removed more times than inserted.
+	NegativelyReferencedHash(H256),
+	/// A committed value was inserted more than once.
+	AlreadyExists(H256),
+}
+
+impl fmt::Display for BaseDataError {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		match *self {
+			BaseDataError::NegativelyReferencedHash(hash) =>
+				write!(f, "Entry {} removed from database more times than it was added.", hash),
+			BaseDataError::AlreadyExists(hash) =>
+				write!(f, "Committed key already exists in database: {}", hash),
+		}
+	}
+}
+
+impl std::error::Error for BaseDataError {
+	fn description(&self) -> &str {
+		"Error in database subsystem"
+	}
+}
+
+error_chain! {
+	types {
+		UtilError, ErrorKind, ResultExt, Result;
+	}
+
+	foreign_links {
+		Io(::std::io::Error);
+		FromHex(FromHexError);
+		Decoder(DecoderError);
+		BaseData(BaseDataError);
+	}
+}
+