As Windyplains said, it's in the mod's source code. You need to activate them by editing the module system files. If you don't know what that is or you're not sure of you're doing I suggest you read up on creating/editing companions. There's a lot of documentation by now.
There's quite some editing yet to do. It's not really hard but it's a little tedious and you have to check a few things particularly in the module_dialogs.py file. Basically they were only added into the module_troops.py (troops.txt when compiled) to prevent save game breaking if you choose to activate them at some point, like Windyplains said.