B-Trees and a User Guide

Release cowdb0.8.7 is out, and it includes b-trees and range iterators. I've also added a basic user guide to the Wiki. Check it out at
http://agilewiki.wiki.sourceforge.net/CowDb

Oh, and here's the updated feature list:

• Light Weight A small memory footprint, but with a configurable cache size.
• Simple Operation Each database has a single disk file. No log files; no before image files.
• Highly robust Fully transactional. Recovery is fast and fully automated.
• Branches (virtual deep copies) can be done at any level.
• Extensible Hashes for fast access to large collections.
• B-Trees for ordered access to large collections. Includes range iterators.
• Long Running Queries An advanced threading model allows long running queries to continue on one branch while updates execute in other branches in the same database.
• Extensible Almost every object used in the implementation has an interface. And the factory pattern is used throughout. New application objects can be defined by subclassing PersistentObject (and extending the factory) or objects can be stored in a container for Serializable POJOs. Byte arrays are also supported.
• Framework Free Injection Of Control (IOC) is used in place of a complex framework. This significantly reduces the complexity as well as making it easier to understand.
• Conditional Compression Large objects are compressed; small objects are not.
• Common Context Object methods and methods both operate within the context of an index, so the same programming style can be used.
• Navigatable Context A transaction can easily migrate from one context to another by selecting another index.
• Symbolic Links Both direct references (disk offset) and symbolic links (named access via an index) are supported.