* Implement last_checkpoint_storage_at
* Add reverted_storage_at for externalities
* sstore_clears_count -> sstore_clears_refund
* Implement eip1283 for evm
* Add eip1283Transition params
* evm: fix tests
* jsontests: fix test
* Return checkpoint index when creating
* Comply with spec Version II
* Fix docs
* Fix jsontests feature compile
* Address grumbles
* Fix no-checkpoint-entry case
* Remove unnecessary expect
* Add test for State::checkpoint_storage_at
* Add executive level test for eip1283
* Hard-code transaction_checkpoint_index to 0
* Fix jsontests
* Add tests for checkpoint discard/revert
* Require checkpoint to be empty for kill_account and commit
* Get code coverage
* Use saturating_add/saturating_sub
* Fix issues in insert_cache
* Clear the state again
* Fix original_storage_at
* Early return for empty RLP trie storage
* Update comments
* Fix borrow_mut issue
* Simplify checkpoint_storage_at if branches
* Better commenting for gas handling code
* Address naming grumbles
* More tests
* Fix an issue in overwrite_with
* Add another test
* Fix comment
* Remove unnecessary bracket
* Move orig to inner if
* Remove test coverage for this PR
* Add tests for executive original value
* Add warn! for an unreachable cause
* Allow post-homestead forks to be specified in CommonParams
* Fix all json configs
* Fix test in json crate
* Fix test in ethcore
* Fix all chain configs to use tabs
Given we use tabs in .editorconfig and the majority of chain configs.
This change is done in Emacs using `mark-whole-buffer` and `indent-region`.
* move common forks and parameters to common params
* port specs over to new format
* fix RPC tests
* parity-machine skeleton
* remove block type
* extract out ethereum-specific methods into EthereumMachine
* beginning to integrate Machine into engines. dealing with stale transitions in Ethash
* initial porting to machine
* move block reward back into engine
* abstract block reward logic
* move last hash and DAO HF logic into machine
* begin making engine function parameters generic
* abstract epoch verifier and ethash block reward logic
* instantiate special ethereummachine for ethash in spec
* optional full verification in verify_block_family
* re-instate tx_filter in a way that works for all engines
* fix warnings
* fix most tests, further generalize engine trait
* uncomment nullengine, get ethcore tests compiling
* fix warnings
* update a bunch of specs
* re-enable engine signer, validator set, and transition handler
* migrate basic_authority engine
* move last hashes into executedblock
* port tendermint
* make all ethcore tests pass
* json-tests compilation
* fix RPC tests: change in gas limit for new block changed PoW hash
* fix minor grumbles
* validate chainspecs
* fix broken import
* fix transaction verification for pre-homestead