Drop system

Working:
-Multiple drops with configurable drop chances
-Shotgun and health drops tested
-Shotgun comes back if picked up once you run out of ammo

To improve:
-Refreshing perks (time/ammo reset) if duplicate
-Getting working weapon buff perks, applied to all weapons
-Overwriting 3rd weapon slot if weapon drop is different gun
-Auto switching to 3rd weapon if new