* Update a few dependencies
Updates two dependencies: `kvdb-rocksdb` and `h2`. Brings in `parking_lot 0.9` which is unintended but possibly fine.
* Bump parking_lot to 0.9
Bump kvdb-memorydb to 0.2 (from git atm)
* New kvdb-memorydb is not breaking
* Remove [patch]
- Refactor (and rename crate) and implement RwLock len cache.
- improve docs
- update ethcore verification queue to new version
- Implement Default, From, also derive Debug
- update: parking_lot to 0.7
