Basic Authority (#991)

* Firt commit.

* First non-functional but correct implementation of BasicAuthority.

Still needs:
- Sealing infrastructure.

* Punch a hole to give miner access to key store.

* Fix test built.

* Basic version of synchronous mining.

This will seal a block whenever a new transaction comes through.
To be made better we need a timer which will wait for one second after the
last block before sealing a new one - better still would be to cooperatively
interleave blocks with other sealing nodes.

* Add tests.

* Fix minor issues from repotting.

* Address grumbles.

json/src/spec/basic_authority.rs

@@ -0,0 +1,59 @@
+// Copyright 2015, 2016 Ethcore (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/>.
+
+//! Ethash params deserialization.
+
+use uint::Uint;
+use hash::Address;
+
+/// Ethash params deserialization.
+#[derive(Debug, PartialEq, Deserialize)]
+pub struct BasicAuthorityParams {
+	/// Gas limit divisor.
+	#[serde(rename="gasLimitBoundDivisor")]
+	pub gas_limit_bound_divisor: Uint,
+	/// Block duration.
+	#[serde(rename="durationLimit")]
+	pub duration_limit: Uint,
+	/// Valid authorities
+	pub authorities: Vec<Address>,
+}
+
+/// Ethash engine deserialization.
+#[derive(Debug, PartialEq, Deserialize)]
+pub struct BasicAuthority {
+	/// Ethash params.
+	pub params: BasicAuthorityParams,
+}
+
+#[cfg(test)]
+mod tests {
+	use serde_json;
+	use spec::basic_authority::BasicAuthority;
+
+	#[test]
+	fn basic_authority_deserialization() {
+		let s = r#"{
+			"params": {
+				"gasLimitBoundDivisor": "0x0400",
+				"durationLimit": "0x0d",
+				"authorities" : ["0xc6d9d2cd449a754c494264e1809c50e34d64562b"]
+			}
+		}"#;
+
+		let _deserialized: BasicAuthority = serde_json::from_str(s).unwrap();
+	}
+}