Extract some parts of miner from ethcore. (#7353)

* Move miner away from ethcore.

* Fix ethcore to use miner/transaction.

* Fix tests and warnings.

* fixed incorrect merge of the test in the documentation

sync/src/tests/consensus.rs

@@ -22,9 +22,9 @@ use ethcore::client::{BlockChainClient, Client};
 use ethcore::service::ClientIoMessage;
 use ethcore::spec::Spec;
 use ethcore::miner::MinerService;
-use ethcore::transaction::*;
 use ethcore::account_provider::AccountProvider;
 use ethkey::{KeyPair, Secret};
+use transaction::{Action, PendingTransaction, Transaction};
 use super::helpers::*;
 use SyncConfig;