* remove register_account_provider
* build rpc module
* new dummy client
* common EngineSigner struct
* from -> into
* initial report via call
* separate safe from regular contract
* transact_contract
* fix build
* return Signature, docs
* add sign method to some engines
* add safeContract spec
* update specs to new contracts
* use AuthorityRound for contract spec
* add more reporting
* add reporting test
* use gas floor
* shorter
