-added absen components list to system

-added ECS uda attributes
-added InputStruct version switch (gets update() input as structure of arrays)
-initial (WIP) EntitiesData update() input structure compile time parsing

source/ecs/system.d

@@ -39,6 +39,7 @@ package:
     void* m_system_pointer;
 
     ushort[] m_components;
+    ushort[] m_absen_components;
     ushort[] m_optional_components;
 
     //void function(ref EntityManager.CallData data, void* entity) update;