Generalize engine trait (#6591)

* move common forks and parameters to common params

* port specs over to new format

* fix RPC tests

* parity-machine skeleton

* remove block type

* extract out ethereum-specific methods into EthereumMachine

* beginning to integrate Machine into engines. dealing with stale transitions in Ethash

* initial porting to machine

* move block reward back into engine

* abstract block reward logic

* move last hash and DAO HF logic into machine

* begin making engine function parameters generic

* abstract epoch verifier and ethash block reward logic

* instantiate special ethereummachine for ethash in spec

* optional full verification in verify_block_family

* re-instate tx_filter in a way that works for all engines

* fix warnings

* fix most tests, further generalize engine trait

* uncomment nullengine, get ethcore tests compiling

* fix warnings

* update a bunch of specs

* re-enable engine signer, validator set, and transition handler

* migrate basic_authority engine

* move last hashes into executedblock

* port tendermint

* make all ethcore tests pass

* json-tests compilation

* fix RPC tests: change in gas limit for new block changed PoW hash

* fix minor grumbles

* validate chainspecs

* fix broken import

* fix transaction verification for pre-homestead

json/src/spec/authority_round.rs

@@ -40,6 +40,9 @@ pub struct AuthorityRoundParams {
 	/// Whether transitions should be immediate.
 	#[serde(rename="immediateTransitions")]
 	pub immediate_transitions: Option<bool>,
+	/// Reward per block in wei.
+	#[serde(rename="blockReward")]
+	pub block_reward: Option<Uint>,
 }
 
 /// Authority engine deserialization.
@@ -67,7 +70,8 @@ mod tests {
 					"list" : ["0xc6d9d2cd449a754c494264e1809c50e34d64562b"]
 				},
 				"startStep" : 24,
-				"validateStepTransition": 150
+				"validateStepTransition": 150,
+				"blockReward": 5000000
 			}
 		}"#;
 
@@ -76,5 +80,6 @@ mod tests {
 		assert_eq!(deserialized.params.validators, ValidatorSet::List(vec![Address(H160::from("0xc6d9d2cd449a754c494264e1809c50e34d64562b"))]));
 		assert_eq!(deserialized.params.start_step, Some(Uint(U256::from(24))));
 		assert_eq!(deserialized.params.immediate_transitions, None);
+
 	}
 }