Update NullBot to the latest version, include Turtle and Hover AI
Reformat some messages to fit correctly in the console area.
Don't retry UPnP configuration after it failed, and while still in the game lobby screen.
(You need to exit out of the game lobby screen to retry UPnP configuration.)
Remove UPnP entry in router on game quit.
Merge branch 'bugfixes' into 3.1