* Revert non-best block
This makes `revert` also revert non-best blocks.
* Update client/db/src/lib.rs
* Do not count leaves against the maximum number to revert
* Add some explanation
* Fix bug
* Apply suggestions from code review
Co-authored-by: Davide Galassi <davxy@datawok.net>
Co-authored-by: Davide Galassi <davxy@datawok.net>