Update 1.51d: Improvements

- Addition: New game icon - Improvement: Shot animations - Improvement: Recoil intensity of firearms - Improvement: Camera shake movement when firing in first-person view - Improvement: Soldiers' acceleration speed - Improvement: Enemy's vision is synchronized with their head rotation - Fix: Operators might not be displayed in the correct order in the radial menu for switching operators - Fix: The camera movement while shooting with a weapon could have slight unwanted jitters - Fix: "VK-18" assault rifle did not have the correct iron sights