Provides a framework for rule based text scanning and uses the framework to provide rule-driven default implementations of `IPresentationDamager`, `IPresentationRepairer` and `IDocumentPartitioner`.

## Package Specification

`RuleBasedScanner` is a document-based scanner controlled by `IRule` objects. When evaluated an `IRule` always returns an `IToken`. The package provides a set of rules whereby `PatternRule` is the most important one. `PatternRule` defines a pattern-configurable rule.