Add CBM Artificial Night

CBM artificial night blocks out the sun, eliminating all natural light. In testing, in combination with olfactory mask and night vision, I observed zombies wander aimlessly in my vicinity. If I moved, they followed, presumably from sound. If I deactivated artificial night, they came straight for me.

It has the same rarity/installation difficulty as CBM cloak and is listed with cloak in mapitemsdef.cpp, but only costs 1/4 the power to sustain (1 per 2 turns).