Initial convertion of a_Dt to std::chrono

also refactored cWorld::m_WorldAge and cWorld::m_TimeOfDay

src/Entities/HangingEntity.h

@@ -43,7 +43,7 @@ public:
 private:
 
 	virtual void SpawnOn(cClientHandle & a_ClientHandle) override;
-	virtual void Tick(float a_Dt, cChunk & a_Chunk) override {}
+	virtual void Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk) override {}
 
 	eBlockFace m_Facing;