Duplicate your production and improve UPS with Dupeboxes - multithreaded production buildings

Usage:
- Use Dupebox Planner item to copy a design
- Plop down some copies of it
- place Dupebox Transfer Belts for input/output. Belts should be loaded with sane item on both sides of belt!
- Wait until bots build all ghosts
- Open train stop and press ACTIVATE button
- To build more things, go inside Dupebox and place some buildings or ghosts

How it works:
Mod takes N belts of same input and resuces them to 1 belt which goes into the box
Produced 1 belt of items is multiplied back to N belts of output
Mod uses pure combinator-based design you may see under dupebox, so it should be very UPS-efficient
Power and liqued transfer is not done yet, you may use biolers or solar inside box for now