General: Clean up inclusions

Ensures that each header includes all of its dependencies that can't be
forward declared.

include/amuse/AudioGroupProject.hpp

@@ -1,11 +1,13 @@
 #pragma once
 
-#include "Entity.hpp"
-#include "Common.hpp"
-#include <vector>
 #include <array>
-#include <unordered_map>
 #include <memory>
+#include <unordered_map>
+#include <vector>
+
+#include "amuse/Common.hpp"
+
+#include <athena/DNA.hpp>
 
 namespace amuse {
 class AudioGroupData;