Update 1.54c: Improvements

[p]- Addition: New gameplay option - Dark Night[/p][p]- Addition: Character selected in Photo Mode during a mission is now highlighted for better visibility[/p][p]- Addition: Camera movement when switching firearms[/p][p]- Improvement: Distant gunfire sound propagation[/p][p]- Improvement: Optimized environmental light reflections[/p][p]- Fix: Role-icon display error when no role is assigned[/p][p]- Fix: Enemy AI could sometimes fail to stop their ambient animations correctly when they became alert[/p][p]- Fix: AI navigation error on certain stairs[/p][p]- Fix: Destroyed vehicles in the map editor could sometimes not be selected[/p]