* fix modexp bug: return 0 if base=0 (#6424) * Running state test using parity-evm (#6355) * Initial version of state tests. * Refactor state to support tracing. * Unify TransactResult. * Add test. * Byzantium updates
* split out types into separate crate * split out evm into its own crate
* Fix stack display. * Additional compatiblity fixes.
* Revamping evmbin to support spec files, json format and subcalls. * Fix formatting of usage.