Are those classes part of Flex SDK or upcoming release of LiveCycle Data Services 3?
Flash Builder and Flex use the classes in the fr.* packages in conjunction with the new data-driven development features in Flash Builder. When you import or create a data service in Flash Builder (such as a remote PHP, CFC, web service, HTTP service), a set of ActionScript classes are generated to facilitate working with the service. For example, service wrapper classes and value object classes (really entity objects) are generated. These classes implement, extend, or otherwise depend on code in the fr.* packages.