Validator/authority contract (#3937)

* dir

* simple validator list

* stub validator contract

* make the engine hold Weak<Client> instead of IoChannel

* validator set factory

* register weak client with ValidatorContract

* check chain security

* add address array to generator

* register provider contract

* update validator set on notify

* add validator contract spec

* simple list test

* split update and contract test

* contract change

* use client in tendermint

* fix deadlock

* step duration in params

* adapt tendermint tests

* add storage fields to test spec

* constructor spec

* execute under wrong address

* create under correct address

* revert

* validator contract constructor

* move genesis block lookup

* add removal ability to contract

* validator contract adding validators

* fix basic authority

* validator changing test

* more docs

* update sync tests

* remove env_logger

* another env_logger

* cameltoe

* hold EngineClient instead of Client

* add a comment about lock scope

json/src/spec/authority_round.rs

@@ -17,7 +17,7 @@
 //! Authority params deserialization.
 
 use uint::Uint;
-use hash::Address;
+use super::ValidatorSet;
 
 /// Authority params deserialization.
 #[derive(Debug, PartialEq, Deserialize)]
@@ -29,7 +29,7 @@ pub struct AuthorityRoundParams {
 	#[serde(rename="stepDuration")]
 	pub step_duration: Uint,
 	/// Valid authorities
-	pub authorities: Vec<Address>,
+	pub validators: ValidatorSet,
 	/// Block reward.
 	#[serde(rename="blockReward")]
 	pub block_reward: Option<Uint>,
@@ -57,7 +57,9 @@ mod tests {
 			"params": {
 				"gasLimitBoundDivisor": "0x0400",
 				"stepDuration": "0x02",
-				"authorities" : ["0xc6d9d2cd449a754c494264e1809c50e34d64562b"],
+				"validators": {
+					"list" : ["0xc6d9d2cd449a754c494264e1809c50e34d64562b"]
+				},
 				"blockReward": "0x50",
 				"startStep" : 24
 			}