Simple more slaves

A simple patch mod that uses a bit of code taken from More Slaves to add more slaves to faction settlements. Note that it only adds slaves to settlements and orbital traders, not slave trade caravans. I might update this to add more slaves to trade caravans if I can figure out how patching works without getting a migrane. Syrchalis is the original author and the code belongs to them, I have simply taken a piece of it for this simple patch mod.