Added support for derived predicates in goals.

By accident, the support for derived predicates in goals was missing.
This commit adds this, in a very similar way to how normal predicates
are handled in the goal description.

src/plasp/pddl/TranslatorASP.cpp

@@ -463,7 +463,7 @@ void TranslatorASP::translateGoal() const
 	m_outputStream << colorlog::Heading2("goal");
 
 	const auto &goal = m_description.problem.value()->goal.value();
-	// TODO: refactor
+
 	::plasp::pddl::translateGoal(m_outputStream, goal);
 
 	m_outputStream << std::endl;