Fix some tooltips

This does not fix the issue I just created, which I discovered while trying to do what this PR does. 

Here, I introduce a tooltip for the Lobby Preset button, improve the grammar in text regarding country flag help and game rules, simplify the country flag logic, and have the map description version default to '1' not 'N/A'. All of this is tiny, pedantic changes I think make the lobby a tiny bit more professional in appearance.
This doesn't apply cleanly after a patch by @ChrisKitching. I'm not sure how it should be done, and I don't have the time to figure it out just now.