Initial: Offchain Workers (#1942)

* Refactor state-machine stuff.

* Fix tests.

* WiP

* WiP2

* Service support for offchain workers.

* Service support for offchain workers.

* Testing offchain worker.

* Initial version working.

* Pass side effects in call.

* Pass OffchainExt in context.

* Submit extrinsics to the pool.

* Support inherents.

* Insert to inherents pool.

* Inserting to the pool asynchronously.

* Add test to offchain worker.

* Implement convenience syntax for modules.

* Dispatching offchain worker through executive.

* Fix offchain test.

* Remove offchain worker from timestamp.

* Update Cargo.lock.

* Address review comments.

* Use latest patch version for futures.

* Add CLI parameter for offchain worker.

* Fix compilation.

* Fix test.

* Fix extrinsics format for tests.

* Fix RPC test.

* Bump spec version.

* Fix executive.

* Fix support macro.

* Address grumbles.

* Bump runtime

substrate/core/cli/src/lib.rs

@@ -419,11 +419,20 @@ where
 			service::Roles::FULL
 		};
 
+	let exec = cli.execution_strategies;
 	config.execution_strategies = ExecutionStrategies {
-		syncing: cli.syncing_execution.into(),
-		importing: cli.importing_execution.into(),
-		block_construction: cli.block_construction_execution.into(),
-		other: cli.other_execution.into(),
+		syncing: exec.syncing_execution.into(),
+		importing: exec.importing_execution.into(),
+		block_construction: exec.block_construction_execution.into(),
+		offchain_worker: exec.offchain_worker_execution.into(),
+		other: exec.other_execution.into(),
+	};
+
+	config.offchain_worker = match (cli.offchain_worker, role) {
+		(params::OffchainWorkerEnabled::WhenValidating, service::Roles::AUTHORITY) => true,
+		(params::OffchainWorkerEnabled::Always, _) => true,
+		(params::OffchainWorkerEnabled::Never, _) => false,
+		(params::OffchainWorkerEnabled::WhenValidating, _) => false,
 	};
 
 	config.roles = role;