Improve logging and cleanup in miner around block sealing (#10745)

* Stop breaking out of loop if a non-canonical hash is found

* include expected hash in log msg

* More logging

* Scope

* Syntax

* Log in blank RollingFinality
Escalate bad proposer to warning

* Check validator set size: warn if 1 or even number

* More readable code

* Use SimpleList::new

* Extensive logging on unexpected non-canonical hash

* Wording

* wip

* Update ethcore/blockchain/src/blockchain.rs

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* Improved logging, address grumbles

* Update ethcore/src/engines/validator_set/simple_list.rs

Co-Authored-By: Luke Schoen <ltfschoen@users.noreply.github.com>

* Report benign misbehaviour iff currently a validator

* Report malicious behaviour iff we're a validator

* Escalate to warning and fix wording

* Test reporting behaviour
Don't require node to be part of the validator set to report malicious behaviour

* Include missing parent hash in MissingParent error

* Update ethcore/src/engines/validator_set/simple_list.rs

Co-Authored-By: Luke Schoen <ltfschoen@users.noreply.github.com>

* docs

* remove unneeded into()
Move check for parent_step == step for clarity&efficiency
Remove dead code for Seal::Proposal

* typo

* Wording

* naming

* WIP

* cleanup

* cosmetics

* cosmetics and one less lvar

* spelling

* Better loggin when a block is already in chain

* More logging

* On second thought non-validators are allowed to report

* cleanup

* remove dead code

* Keep track of the hash of the last imported block

* Let it lock

* Serialize access to block sealing

* Take a lock while sealing a block

* Cleanup

* whitespace

miner/using-queue/src/lib.rs

@@ -14,9 +14,9 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Ethereum.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Queue-like datastructure including notion of usage.
+//! Queue-like data structure including notion of usage.
 
-/// Special queue-like datastructure that includes the notion of
+/// Special queue-like data structure that includes the notion of
 /// usage to avoid items that were queued but never used from making it into
 /// the queue.
 pub struct UsingQueue<T> {
@@ -42,7 +42,7 @@ impl<T> UsingQueue<T> {
 		UsingQueue {
 			pending: None,
 			in_use: vec![],
-			max_size: max_size,
+			max_size,
 		}
 	}