Contains crawl data models shared by the crawling-process and converting-process.
To ensure backward compatibility with older versions of the data, the serialization is abstracted away from the model classes. The models are serialized with the Slop library.
These serialization classes automatically negotiate the serialization format based on the file extension.
Data is accessed through a SerializableCrawlDataStream, which is a somewhat enhanced Iterator that can be used to read data.