Polkadot service (#82)

* Block import notifications

* Build fix

* Consensus messages supported in the networking

* Started consensus service

* BFT service

* Transaction propagation

* Polkadot service

* CLI integration

* Build fix

* Added signatures validation

* Removed executor argument

* Refactored steam loops; Queue size increased

* Limit queue size

* Fixed doc comment

* Fixed wasm build

* Fixed wasm build

* Check id properly

substrate/polkadot/service/src/error.rs

@@ -0,0 +1,35 @@
+// 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/>.
+
+//! Errors that can occur during the service operation.
+
+use client;
+use network;
+
+error_chain! {
+	links {
+		Client(client::error::Error, client::error::ErrorKind) #[doc="Client error"];
+		Network(network::error::Error, network::error::ErrorKind) #[doc="Network error"];
+	}
+
+	errors {
+		/// Key store errors
+		Keystore(e: ::keystore::Error) {
+			description("Keystore error"),
+			display("Keystore error: {:?}", e),
+		}
+	}
+}