We have to make an extra allocation per db get request because key generation function to_key takes Vec. Taking byte slice (AsRef<[u8]> to be precise) also simplifes the code a bit.
Currently Writable accepts trait Write as a type parameter but Readable
takes Read as a trait object, which is not symmetrical and also less performant. This PR changes Readable trait and all places where it's used
* dynamically resize lmdb
* rustfmt
* explicitly close db before resizing
* rustfmt
* test fix
* rustfmt
* pool tests
* chain fix
* merge
* move RwLock into Store, ensure resize gives a min threshold
* rustfmt
* move locks based on testing
* rustfmt
