* 3. Removed extra `jail` prefix in the jail package
* Removed sendMessage and showSuggestions handlers because they're already set in registerHandlers()
* Remove extra asserts
* Changed assertions everywhere to testify
* Exposed JailCell.Call and removed Jail.Cell duplicate method
* Fixed review comments
IMPORTANT: The known issue is that in case of configured UpstreamRPCServer transactions are sent immediately not waiting for CompleteTransaction or DiscardTransaction which brings inconsistency in behaviour and acts as a security breach.
* new UpstreamRPConfig in geth/params to provide upstream configuration
* conditional start of ethereum blockchain sequence based on NodeConfig.UpstreamConfig.Enabled flag state
* Fixed tests (only when they run one by one; they can still fail if run together)
* Fixed TestJailSendQueuedTransaction: the second command in case 4 was altering status.message_id and thus the test was failing. Earlier it had been working because cells were cloned during every Call
* Added a check into TestJailVMPersistence: now its concurrent-resiliency is asserted
* Fixed CallRPC: shh_version now return "5.0" instead of "0x5"
* Fixed TestWhisperFilterRace: there was changed Whisper API which should just be adhered to
* Fixed geth1.6.7 rebase consequences: primarily genesis blocks which now contain metropolishash
- node: signals and node reset, fixes#152
- tests update (testify is used)
- node manager refactored, race conditions fixed
- node wrapper has been removed, we rely on go-ethereum node now
- tx queue refactored
- jail refactored
- backend and API introduced
