* Add some chainspec tests and make sure we validate it.
* Manual implementation of Extension + Forks definitions.
* Move chain spec to separate crate.
* Allow using ChainSpec with extensions.
* Renames.
* Implement Extension derive.
* Implement Extension for Forks.
* Support specifying fork blocks.
* make for_blocks work
* Support forks correctly.
* Add a bunch of docs.
* Make fork blocks optional.
* Add missing docs.
* Fix build.
* Use struct for check_block params.
* Fix tests?
* Clean up.
Tomasz Drwięga