removed engine retrieval from client public api

ethcore/src/client/client.rs

@@ -430,10 +430,6 @@ impl<V> BlockChainClient for Client<V> where V: Verifier {
 		block.try_seal(self.engine.deref().deref(), seal)
 	}
 
-	fn engine(&self) -> &Engine {
-		self.engine.deref().deref()
-	}
-
 	// TODO [todr] Should be moved to miner crate eventually.
 	fn prepare_sealing(&self, author: Address, gas_floor_target: U256, extra_data: Bytes, transactions: Vec<SignedTransaction>)
 		-> (Option<ClosedBlock>, HashSet<H256>) {

ethcore/src/client/mod.rs

@@ -134,12 +134,6 @@ pub trait BlockChainClient : Sync + Send {
 	/// Makes a non-persistent transaction call.
 	fn call(&self, t: &SignedTransaction) -> Result<Executed, ExecutionError>;
 
-	/// Attempt to seal the block internally. See `Engine`.
-	fn generate_seal(&self, block: &ExecutedBlock, accounts: Option<&AccountProvider>) -> Option<Vec<Bytes>> { self.engine().generate_seal(block, accounts) }
-
-	/// Executes a function providing it with a reference to an engine.
-	fn engine(&self) -> &Engine;
-
 	/// Returns traces matching given filter.
 	fn filter_traces(&self, filter: TraceFilter) -> Option<Vec<LocalizedTrace>>;
 

ethcore/src/client/test_client.rs

@@ -430,10 +430,6 @@ impl BlockChainClient for TestBlockChainClient {
 		}
 	}
 
-	fn engine(&self) -> &Engine {
-		unimplemented!();
-	}
-
 	fn filter_traces(&self, _filter: TraceFilter) -> Option<Vec<LocalizedTrace>> {
 		unimplemented!();
 	}

miner/src/miner.rs

@@ -121,7 +121,7 @@ impl Miner {
 			Some(old_block) => {
 				trace!(target: "miner", "Already have previous work; updating and returning");
 				// add transactions to old_block
-				let e = chain.engine();
+				let e = self.engine();
 				let mut invalid_transactions = HashSet::new();
 				let mut block = old_block.reopen(e);
 				let block_number = block.block().fields().header.number();
@@ -277,7 +277,7 @@ impl MinerService for Miner {
 				state.sub_balance(&sender, &balance);
 				state.add_balance(&sender, &U256::max_value());
 				let options = TransactOptions { tracing: false, check_nonce: false };
-				Executive::new(&mut state, &env_info, chain.engine()).transact(t, options)
+				Executive::new(&mut state, &env_info, self.engine()).transact(t, options)
 			},
 			None => {
 				chain.call(t)