Extract spec to own crate (#10978)

* Add client-traits crate
Move the BlockInfo trait to new crate

* New crate `machine`
Contains code extracted from ethcore that defines `Machine`, `Externalities` and other execution related code.

* Use new machine and client-traits crates in ethcore

* Use new crates machine and client-traits instead of ethcore where appropriate

* Fix tests

* Don't re-export so many types from ethcore::client

* Fixing more fallout from removing re-export

* fix test

* More fallout from not re-exporting types

* Add some docs

* cleanup

* import the macro edition style

* Tweak docs

* Add missing import

* remove unused ethabi_derive imports

* Use latest ethabi-contract

* Move many traits from ethcore/client/traits to client-traits crate
Initial version of extracted Engine trait

* Move snapshot related traits to the engine crate (eew)

* Move a few snapshot related types to common_types
Cleanup Executed as exported from machine crate

* fix warning

* Gradually introduce new engine crate: snapshot

* ethcore typechecks with new engine crate

* Sort out types outside ethcore

* Add an EpochVerifier to ethash and use that in Engine.epoch_verifier()
Cleanup

* Document pub members

* Sort out tests
Sort out default impls for EpochVerifier

* Add test-helpers feature and move EngineSigner impl to the right place

* Sort out tests

* Sort out tests and refactor verification types

* Fix missing traits

* More missing traits
Fix Histogram

* Fix tests and cleanup

* cleanup

* Put back needed logger import

* Don't rexport common_types from ethcore/src/client
Don't export ethcore::client::*

* Remove files no longer used
Use types from the engine crate
Explicit exports from engine::engine

* Get rid of itertools

* Move a few more traits from ethcore to client-traits: BlockChainReset, ScheduleInfo, StateClient

* Move ProvingBlockChainClient to client-traits

* Don't re-export ForkChoice and Transition from ethcore

* Address grumbles: sort imports, remove commented out code

* Fix merge resolution error

* Extract the Clique engine to own crate

* Extract NullEngine and the block_reward module from ethcore

* Extract InstantSeal engine to own crate

* Extract remaining engines

* Extract executive_state to own crate so it can be used by engine crates

* Remove snapshot stuff from the engine crate

* Put snapshot traits back in ethcore

* cleanup

* Remove stuff from ethcore

* Don't use itertools

* itertools in aura is legit-ish

* More post-merge fixes

* Re-export less types in client

* cleanup

* Extract spec to own crate

* Put back the test-helpers from basic-authority

* Fix ethcore benchmarks

* Reduce the public api of ethcore/verification

* Update ethcore/block-reward/Cargo.toml

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* Update ethcore/engines/basic-authority/Cargo.toml

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* Update ethcore/engines/ethash/Cargo.toml

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* Update ethcore/engines/clique/src/lib.rs

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* signers is already a ref

* Add an EngineType enum to tighten up Engine.name()

* Introduce Snapshotting enum to distinguish the type of snapshots a chain uses

* Rename supports_warp to snapshot_mode

* Missing import

* Update ethcore/src/snapshot/consensus/mod.rs

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* missing import

* Fix import

* double semi

ethcore/engines/validator-set/src/contract.rs

@@ -146,10 +146,12 @@ impl ValidatorSet for ValidatorContract {
 mod tests {
 	use std::sync::Arc;
 
+	use accounts::AccountProvider;
+	use call_contract::CallContract;
 	use common_types::{header::Header, ids::BlockId};
+	use client_traits::{BlockChainClient, ChainInfo, BlockInfo};
 	use ethcore::{
 		miner::{self, MinerService},
-		spec,
 		test_helpers::generate_dummy_client_with_spec,
 	};
 	use ethereum_types::{H520, Address};
@@ -157,9 +159,7 @@ mod tests {
 	use parity_bytes::ToPretty;
 	use rlp::encode;
 	use rustc_hex::FromHex;
-	use accounts::AccountProvider;
-	use call_contract::CallContract;
-	use client_traits::{BlockChainClient, ChainInfo, BlockInfo};
+	use spec;
 
 	use super::super::ValidatorSet;
 	use super::ValidatorContract;

ethcore/engines/validator-set/src/multi.rs

@@ -156,22 +156,21 @@ mod tests {
 	use std::collections::BTreeMap;
 
 	use accounts::AccountProvider;
-	use client_traits::{BlockChainClient, BlockInfo, ChainInfo, ImportBlock, EngineClient};
 	use common_types::{
 		header::Header,
 		ids::BlockId,
 		verification::Unverified,
 	};
+	use client_traits::{BlockChainClient, BlockInfo, ChainInfo, ImportBlock, EngineClient};
 	use engine::EpochChange;
-
-	use ethkey::Secret;
 	use ethcore::{
 		miner::{self, MinerService},
 		test_helpers::{generate_dummy_client_with_spec, generate_dummy_client_with_spec_and_data},
-		spec,
 	};
 	use ethereum_types::Address;
+	use ethkey::Secret;
 	use keccak_hash::keccak;
+	use spec;
 
 	use crate::ValidatorSet;
 	use super::Multi;

ethcore/engines/validator-set/src/safe_contract.rs

@@ -251,7 +251,7 @@ impl ValidatorSafeContract {
 
 		LogEntry {
 			address: self.contract_address,
-			topics: topics,
+			topics,
 			data: Vec::new(), // irrelevant for bloom.
 		}.bloom()
 	}
@@ -467,7 +467,6 @@ mod tests {
 	use client_traits::{BlockInfo, ChainInfo, ImportBlock, EngineClient};
 	use engine::{EpochChange, Proof};
 	use ethcore::{
-		spec,
 		miner::{self, MinerService},
 		test_helpers::{generate_dummy_client_with_spec, generate_dummy_client_with_spec_and_data}
 	};
@@ -475,6 +474,7 @@ mod tests {
 	use ethereum_types::Address;
 	use keccak_hash::keccak;
 	use rustc_hex::FromHex;
+	use spec;
 
 	use super::super::ValidatorSet;
 	use super::{ValidatorSafeContract, EVENT_NAME_HASH};