Polkadot service (#82)

* Block import notifications

* Build fix

* Consensus messages supported in the networking

* Started consensus service

* BFT service

* Transaction propagation

* Polkadot service

* CLI integration

* Build fix

* Added signatures validation

* Removed executor argument

* Refactored steam loops; Queue size increased

* Limit queue size

* Fixed doc comment

* Fixed wasm build

* Fixed wasm build

* Check id properly

substrate/demo/cli/src/lib.rs

@@ -41,6 +41,7 @@ extern crate log;
 
 pub mod error;
 
+use std::sync::Arc;
 use codec::Slicable;
 use demo_runtime::genesismap::{additional_storage_with_genesis, GenesisConfig};
 use client::genesis;
@@ -98,7 +99,7 @@ pub fn run<I, T>(args: I) -> error::Result<()> where
 		storage.extend(additional_storage_with_genesis(&block));
 		(primitives::block::Header::decode(&mut block.header.encode().as_ref()).expect("to_vec() always gives a valid serialisation; qed"), storage.into_iter().collect())
 	};
-	let client = client::new_in_mem(executor, prepare_genesis)?;
+	let client = Arc::new(client::new_in_mem(executor, prepare_genesis)?);
 
 	let address = "127.0.0.1:9933".parse().unwrap();
 	let handler = rpc::rpc_handler(client);