Input system complete (untested)

Escape-the-Dawn/System.h

@@ -11,7 +11,10 @@ public:
 	System(World* world) : m_World(world) { }
 	virtual ~System() { }
 
-	virtual void Update(double dt, EntityID entity, EntityID parent) = 0;
+	// Called once per system every tick
+	virtual void Update(double dt) { }
+	// Called once for every entity in the world every tick
+	virtual void Update(double dt, EntityID entity, EntityID parent) { }
 
 protected:
 	World* m_World;