Consensus Engines Implementation: Aura (#911)

* Generalize BlockImport

 - move ImportBlock, BlockOrigin, ImportResult into shared sr-primitives
 - let Consensus provide  and  traits again
 - update consensus traits to latest development
 - implement traits on client::Client, test_client::TestClient
 - update RHD to use the new import_block API

* Move ImportBlock into consensus-common
* Send import notification in aura tests
* Integrating aura into service
* Make Signatures more generic
* Aura Block Production with the given key
* run aura on the thread pool
* start at exact step start in aura
* Add needed wasm blob, in leiu of better solutions.
* Make API ids consistent with traits and bring upstream for sharing.
* Add decrease_free_balance to Balances module
* Encode `Metadata` once instead of two times
* Bitops include xor
* Upgrade key module.
* Default pages to somewhat bigger.
* Introduce upgrade key into node
* Add `Created` event

substrate/srml/contract/src/tests.rs

@@ -617,6 +617,10 @@ fn top_level_create() {
 				phase: Phase::ApplyExtrinsic(0),
 				event: MetaEvent::contract(RawEvent::Transfer(0, derived_address, 11)),
 			},
+			EventRecord {
+				phase: Phase::ApplyExtrinsic(0),
+				event: MetaEvent::contract(RawEvent::Created(0, 1)),
+			},
 		]);
 	});
 }