Travelling merchants are nearly done. You can buy from their inventory and sell them your crap, or escort them back to town to improve that town's wealth.
The buy menu header isn't sure what to do when there's different types of item.
Option of attacking the merchant. This system can then be used to make encounters with bandits too.
Got to nail down a bug where a merchants inventory sometimes has a NoneType.
Have sold items go into the merchant's inventory.