* Add finality parameter to `null engine`
* Add testcase for finalization marking in `ethcore` client
* Add double cache read for db
* Prevent lost update of block details
* Read with pending update for block details in batch
* Temp storage for the private state added
* Temp storage for the private state added
* Request message added
* Store and retrieve offchain state logic
* State sync cache
* Private state column added to key value db
* Private state column added to key value db
* Indexing stored states via its hash
* Works with errors changed
* Private state stored into the local db
* Access to private state db added to sync io
* Private state db file added
* Rlp packets for retrieiving private state data added
* Handling of private sync completed message
* Test code fixed
* External flag for offchain storing added
* Test for private state sync added
* Saving private state logic corrected
* Migration code corrected
* Fixes after merge with master
* Merge with head
* Additional checks for slices
* Log for private state retrieval added
* Limit time of retrieving private states
* Store required hashes for every request, mark them stale if needed
* Store requested private state hashes and check received data
* Log stale requests
* State insertion fix
* Refactoring of how logging passed to state store
* Heapsize removed, syncing hashes structure reworked
* Check state length returned by contract
* Get rid of OverlayDB
* hash-db version updated
* Test fixed
* One more test fixed
* Run cargo fix on `vm`
* Run cargo fix on ethcore-db
* Run cargo fix on evm
* Run cargo fix on ethcore-light
* Run cargo fix on journaldb
* Run cargo fix on wasm
* Missing docs
* Run cargo fix on ethcore-sync
