Wheeled Carts should be Attachable to Tugs

[Frank_Stein]

I just did it, I added two or cases including the obj/storage/cart types. It seems to work fine.

Also, why aren't there sounds for connecting/disconnecting carts? Seems like an obvious addition.

You could probably use the same sound effect as buckling in chairs. I think that gives across a good "This is connected now" feedback