* 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
* refactor PriceInfo to use Fetch and reuse the client
* forget Fetch future to keep it running in the background
* update Debug message for price_info::Client
* wrap underlying errors in price_info client
* use debug_struct in price_info client debug implementation
* use global fetch service in price_info client
* rename gas_pricer parameter in RunCmd
* move price_info to its own crate
* fix price_info tests
* replace rustc_serialize with serde_json in price_info
* add documentation for price_info
* remove unused rustc-serialize dependency from ethcore
* fix price_info formatting
* re-export fetch crate in price_info
* remove unused cfg attributes in price_info
* add tests for price_info
* Clarify function name
Function checks if sealing is currently underway, not to be confused
with checking whether the engine performs internal sealing.
* Error when work called on internal sealing engine
* Error submitting work for internal sealing engine
* Fix inverted bool and style grumbles
* Add can_produce_work_package to TestMinerService
* Error when setting engine signer on PoW chain
* Unit tests for engine signing
Setting engine signer should fail if chain does not seal internally
or client lacks account provider.
* Tweak TestMinerService
* Fix minor style grumbles
* state backend trait mirroring state_db API
* minimal state backend trait
make state module public
* fix json tests
* return errors on database corruption
* fix tests, json tests
* fix remainder of build
* add Backend bound on state