no need for registerInterceptor private method
adding NoInterceptMethodsValidationRule
removing validation from AspectStyleInterceptorHandler
moving AspectStyleInterceptorHandlerTests
adding AcceptsNeedReturnBooleanValidationRule
moving AspectStyleInterceptorHandlerTest
extracting classes used only for this tests
adding NoStackParamValidationRule
removing NoStackParameterSignatureAcceptor
removing NoStackParameterStepExecutor
moving tests and extracting classes only used in tests