Punish offline validators, aura-style (#1216)

* make offline-reporting infrastructure more generic

* add a listener-trait for watching when the timestamp has been set

* prevent inclusion of empty offline reports

* add test for exclusion

* generate aura-offline reports

* ability to slash many times for being offline "multiple" times

* Logic for punishing validators for missing aura steps

* stub tests

* pave way for verification of timestamp vs slot

* alter aura import queue to wait for timestamp

* check timestamp matches seal

* do inherent check properly

* service compiles

* all tests compile

* test srml-aura logic

* aura tests pass

* everything builds

* some more final tweaks to block authorship for aura

* switch to manual delays before step

* restore substrate-consensus-aura to always std and address grumbles

* update some state roots in executor tests

* node-executor tests pass

* get most tests passing

* address grumbles

substrate/node/runtime/Cargo.toml

@@ -13,9 +13,10 @@ parity-codec-derive = "2.1"
 sr-std = { path = "../../core/sr-std" }
 srml-support = { path = "../../srml/support" }
 substrate-primitives = { path = "../../core/primitives" }
-substrate-finality-grandpa-primitives = { path = "../../core/finality-grandpa/primitives" }
+substrate-consensus-aura-primitives = { path = "../../core/consensus/aura/primitives", default-features = false }
 substrate-client = { path = "../../core/client" }
 substrate-keyring = { path = "../../core/keyring" }
+srml-aura = { path = "../../srml/aura" }
 srml-balances = { path = "../../srml/balances" }
 srml-consensus = { path = "../../srml/consensus" }
 srml-contract = { path = "../../srml/contract" }
@@ -59,5 +60,5 @@ std = [
 	"serde/std",
 	"safe-mix/std",
 	"substrate-client/std",
-	"substrate-finality-grandpa-primitives/std",
+	"substrate-consensus-aura-primitives/std",
 ]