Fix NodeRef dependency on BinaryNode structure.
Moves from_string into BinaryNode for better separation of duties.
Adds thoughts on msgpack todo.
Fixes connect() to work when the db file doesn't already exist, but to not truncate it if it does already exist.
Removes unused :memory: target. If you want to try stubbing things or using your own fh, use DBDB(f) directly.
Rearranges TODOs, adds details.
Adds portalocker to serialize write access to the db.