Slash Authorities for irrefutable misbehavior (#84)

* double-commit and prepare misbehavior

* get misbehavior on completion

* collect misbehavior on drop, not only on success

* kill unused transaction_index field

* add primitive misbehavior report type

* add misbehavior report transaction

* store prior session

* fix set_items

* basic checks for misbehavior reports

* crate for substrate bft misbehavior checking

* integrate misbehavior check crate

* fix comment

* new wasm binaries

* fix hash in test

* import misbehavior transactions into queue

* fix test build

* sign on digest and full proposal when proposing

* detect proposal misbehavior

* fix fallout

* restore balance/bondage types

substrate/substrate/client/src/client.rs

@@ -393,11 +393,16 @@ mod tests {
 		bft::UncheckedJustification {
 			digest: hash,
 			signatures: authorities.iter().map(|key| {
-				bft::sign_message(
-					bft::generic::Message::Commit(1, hash),
+				let msg = bft::sign_message(
+					bft::generic::Vote::Commit(1, hash).into(),
 					key,
 					header.parent_hash
-				).signature
+				);
+
+				match msg {
+					bft::generic::LocalizedMessage::Vote(vote) => vote.signature,
+					_ => panic!("signing vote leads to signed vote"),
+				}
 			}).collect(),
 			round_number: 1,
 		}