Refactor class-relative resource access in one test.
Refactor UKItemIdentificationStrategy test.
Permit unqualified test reference to XML files if setTestingClass has been called.
Refactor resources for UKEntityOrderingStrategy test.
Refactor resources for IPHintValidationStage test.
Refactor resources for IdPDisplayNameDuplicateDetectingStage test.
Refactor resources for RegistrationAuthorityPopulationStage test.
Refactor resources for StatisticsVelocityStage test.
Simplify relative resource handling now that we no longer use "data" directory.