This change was necessary to facilitate the ability to serialize
(create/modify) YAML configuration data. This is a prerequisite to
creating config templates and also GUI work in the future.
YamlSerializerFactory continues to grow as we add parsing features to
YAML files. A new behavior system now provides granular sets of features
to the factory. To extend the functionality of the YAML parser,
implement the `IYamlBehavior` interface. It will automatically be
registered to Autofac and injected into `YamlSerializerFactory`.