* Add Close() function to all the iterators
* Add defer iterator.Close() whenever we open an iterator
* Add isClosed to all iterators and panic/return error if used after closing
Co-authored-by: Svarog <feanorr@gmail.com>
* [NOD-1412] Remove ffldb, and make ldb implement all the database
interfaces
* [NOD-1412] Removed any reference to dataStore and updated block dbaccess to work directly with key/values