Extract engines to own crates (#10966)

* 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

* 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>

* remove double-semicolons

ethcore/engines/basic-authority/res/basic_authority.json

@@ -0,0 +1,46 @@
+{
+	"name": "TestBasicAuthority",
+	"engine": {
+		"basicAuthority": {
+			"params": {
+				"durationLimit": "0x0d",
+				"validators": {
+					"list": ["0x9cce34f7ab185c7aba1b7c8140d620b4bda941d6"]
+				}
+			}
+		}
+	},
+	"params": {
+		"gasLimitBoundDivisor": "0x0400",
+		"accountStartNonce": "0x0100000",
+		"maximumExtraDataSize": "0x20",
+		"minGasLimit": "0x1388",
+		"networkID" : "0x69",
+		"eip140Transition": "0x0",
+		"eip211Transition": "0x0",
+		"eip214Transition": "0x0",
+		"eip658Transition": "0x0"
+	},
+	"genesis": {
+		"seal": {
+			"generic": "0xc180"
+		},
+		"difficulty": "0x20000",
+		"author": "0x0000000000000000000000000000000000000000",
+		"timestamp": "0x00",
+		"parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
+		"extraData": "0x",
+		"gasLimit": "0x2fefd8"
+	},
+	"accounts": {
+		"0000000000000000000000000000000000000001": { "balance": "1", "nonce": "1048576", "builtin": { "name": "ecrecover", "pricing": { "linear": { "base": 3000, "word": 0 } } } },
+		"0000000000000000000000000000000000000002": { "balance": "1", "nonce": "1048576", "builtin": { "name": "sha256", "pricing": { "linear": { "base": 60, "word": 12 } } } },
+		"0000000000000000000000000000000000000003": { "balance": "1", "nonce": "1048576", "builtin": { "name": "ripemd160", "pricing": { "linear": { "base": 600, "word": 120 } } } },
+		"0000000000000000000000000000000000000004": { "balance": "1", "nonce": "1048576", "builtin": { "name": "identity", "pricing": { "linear": { "base": 15, "word": 3 } } } },
+		"0000000000000000000000000000000000000005": { "balance": "1", "builtin": { "name": "modexp", "activate_at": 0, "pricing": { "modexp": { "divisor": 20 } } } },
+		"0000000000000000000000000000000000000006": { "balance": "1", "builtin": { "name": "alt_bn128_add", "activate_at": 0, "pricing": { "linear": { "base": 500, "word": 0 } } } },
+		"0000000000000000000000000000000000000007": { "balance": "1", "builtin": { "name": "alt_bn128_mul", "activate_at": 0, "pricing": { "linear": { "base": 40000, "word": 0 } } } },
+		"0000000000000000000000000000000000000008": { "balance": "1", "builtin": { "name": "alt_bn128_pairing", "activate_at": 0, "pricing": { "alt_bn128_pairing": { "base": 100000, "pair": 80000 } } } },
+		"9cce34f7ab185c7aba1b7c8140d620b4bda941d6": { "balance": "1606938044258990275541962092341162602522202993782792835301376", "nonce": "1048576" }
+	}
+}