[stable] Backports (#8133)

* updater: apply exponential backoff after download failure (#8059)

* updater: apply exponential backoff after download failure

* updater: reset backoff on new release

* Limit incoming connections.  (#8060)

* Limit ingress connections
* Optimized handshakes logging

* Max code size on Kovan (#8067)

* Enable code size limit on kovan

* Fix formatting.

* add some dos protection (#8084)

* more dos protection (#8104)

* Const time comparison (#8113)

* Use `subtle::slices_equal` for constant time comparison.

Also update the existing version of subtle in `ethcrypto` from
0.1 to 0.5

* Test specifically for InvalidPassword error.

* revert removing blooms (#8066)

* Revert "fix traces, removed bloomchain crate, closes #7228, closes #7167"

This reverts commit 1bf62038678295e5586f02a38a0c5aab9a9efe62.

* Revert "fixed broken logs (#7934)"

This reverts commit f8a2e53f3e.

* fixed broken logs

* bring back old lock order

* remove migration v13

* revert CURRENT_VERSION to 12 in migration.rs

* Fix compilation.

* Check one step deeper if we're on release track branches

* add missing pr

* Fix blooms?

* Fix tests compiilation.

* Fix size.

ethcore/src/blockchain/update.rs

@@ -3,6 +3,7 @@ use bigint::hash::H256;
 use header::BlockNumber;
 use blockchain::block_info::BlockInfo;
 use blockchain::extras::{BlockDetails, BlockReceipts, TransactionAddress};
+use blooms::{BloomGroup, GroupPosition};
 
 /// Block extras update info.
 pub struct ExtrasUpdate<'a> {
@@ -18,6 +19,8 @@ pub struct ExtrasUpdate<'a> {
 	pub block_details: HashMap<H256, BlockDetails>,
 	/// Modified block receipts.
 	pub block_receipts: HashMap<H256, BlockReceipts>,
+	/// Modified blocks blooms.
+	pub blocks_blooms: HashMap<GroupPosition, BloomGroup>,
 	/// Modified transaction addresses (None signifies removed transactions).
 	pub transactions_addresses: HashMap<H256, Option<TransactionAddress>>,
 }