* `--mode=off` now works.

* Add Mode::Off as a persistent CLI option.

* "last" not "auto" as default.

* Commit accidentally unsaved file.

* Whitespace

[ci:skip]

* Mode CLI parse fix

* or offline

* Save mode when it gets changed.

* Fix Offline mode

* Fix up mode operations.

* Make passive default, but not overriding.

* Fix test

* Maybe not everyone wants to run an archive node...

* Exposing extra info in RPC

* Proper serialization and client trait API

* The front-end for each hard-fork, also EIP-160.

* Address EIP161 a/c

* Include EIP-161b

* EIP-161 part d.

* Fix test build.

* Fix one test, add another.

* Fix use of bloom & renaming.

* Initial groundwork for EIP-155

* Fix minor bug.

* Fix all tests finally.

* Rest of EIP-155.

* Add tests for EIP-155 algorithm.

Update transaction tests validation.

* Minor reformat.

* Address grumbles.

* Remove unused code.

* Fix SUICIDE gas mechanism and add consensus tests.

* Remove commented code.

* Set Frontier hardfork block number

* Fix warning.

* Transaction tests,