* final engine changes
* migration to v13
* adding and removing pending transitions
* epoch_transition_for
* port snapshot to new engine methods
* final validator set interface
* fix compiler errors
* revert v13/epoch_depth transition
* make call on new epoch
* rolling finality checker
* tests for finality checker
* constructing finality proof upon pending transition
* fix warnings and finality proof checking
* fix compiler warnings in tests
* test fixes
* don't include genesis in finality checking
* change snapshot test chain building logic
* minor refactorings
* fetch epoch transition based on parent, fix divide-by-zero in SimpleList
* fix formatting
* fix ABIs and finality checking in snapshot restoration
* encode signal number in proof
* create more blocks at the end of tests
* update gist to accurate contract code
* test for epoch_transition_for
* fix tests with immediateTransitions parameter
* disable force flag after forcing
* rename ValidatorsChanged to InitiateChange and finalizeSignal to finalizeChange
* a few more validator set tests
* to_rlp takes self by-reference
* clean up some derefs
* out-of-order insertion for blockchain
* implement block rebuilder without verification
* group block chunk header into struct
* block rebuilder does verification
* integrate snapshot service with client service; flesh out implementation more
* initial implementation of snapshot service
* remove snapshottaker trait
* snapshot writer trait with packed and loose implementations
* write chunks using "snapshotwriter" in service
* have snapshot taking use snapshotwriter
* implement snapshot readers
* back up client dbs when replacing
* use snapshot reader in snapshot service
* describe offset format
* use new get_db_path in parity, allow some errors in service
* blockchain formatting
* implement parity snapshot
* implement snapshot restore
* force blocks to be submitted in order
* fix bug loading block hashes in packed reader
* fix seal field loading
* fix uncle hash computation
* fix a few bugs
* store genesis state in db. reverse block chunk order in packed writer
* allow out-of-order import for blocks
* bring restoration types together
* only snapshot the last 30000 blocks
* restore into overlaydb instead of journaldb
* commit version to database
* use memorydbs and commit directly
* fix trie test compilation
* fix failing tests
* sha3_null_rlp, not H256::zero
* move overlaydb to ref_overlaydb, add new overlaydb without on-disk rc
* port archivedb to new overlaydb
* add deletion mode tests for overlaydb
* use new overlaydb, check state root at end
* share chain info between state and block snapshotting
* create blocks snapshot using blockchain directly
* allow snapshot from arbitrary block, remove panickers from snapshot creation
* begin test framework
* blockchain chunking test
* implement stateproducer::tick
* state snapshot test
* create block and state chunks concurrently, better restoration informant
* fix tests
* add deletion mode tests for overlaydb
* address comments
* more tests
* Fix up tests.
* remove a few printlns
* add a little more documentation to `commit`
* fix tests
* fix ref_overlaydb test names
* snapshot command skeleton
* revert ref_overlaydb renaming
* reimplement snapshot commands
* fix many errors
* everything but inject
* get ethcore compiling
* get snapshot tests passing again
* instrument snapshot commands again
* fix fallout from other changes, mark snapshots as experimental
* optimize injection patterns
* do two injections
* fix up tests
* take snapshots from 1000 blocks efore
* address minor comments
* fix a few io crate related errors
* clarify names about total difficulty
[ci skip]
* use bloomchain crate in blockchain module. remove obsole chainfilter submodule
* update database version to 6.0
* removed redundant line
* simple db migration
* make migration slightly more functional
* bloomchain migration
* migration version is just a single unsigned integer
* updated migration v6
* parity migration
* db migration
* removed hardcoded migration dir
* replace ptr::copy with clone_from_slice, removed potential endianess problem from trace/db.rs
* removed superfluous line
* blockchains log blooms config is not exposed any more
