Networking and in-memory client (#38)

* Networking crate draft

* Started work on syncing algo

* Fixed query range

* BlockCollection tests

* In-mem client backend

* Fixed tests

* Renamed Transaction

* Removed stray println

* Docs

substrate/network/src/error.rs

@@ -0,0 +1,31 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.?
+
+use network::Error as NetworkError;
+use client;
+
+error_chain! {
+	foreign_links {
+		Network(NetworkError) #[doc = "Devp2p error."];
+	}
+
+	links {
+		Client(client::error::Error, client::error::ErrorKind);
+	}
+
+	errors {
+	}
+}