Adds the janibelt!

The latest in JaniCo inventions, the janibelt allows the user to hold a wide amount of janitorial items throughout their posting on board their assigned stations.

The Janibelt spawns inside Janitor Closets, holds up 6 items, and can hold the following items.

- Flashlight
- Light Replacer
- Cleaner Grenades
- Spray Bottle
- Soap
- Caution Sign