Code review comment for lp:~widelands-dev/widelands/dynamic_tribe_loading

I'd definitely want to try this in a different branch, as I expect the changes to be big.

I also can't deal with all your suggestions below in a teeny tiny VM window, so finishing this branch will have to wait until next month. It would still be great though if you had time for more reviews while I'm gone, so that I can start proposing more of my branches for merge when I get back home.