[Freeciv] Unmanned Colonization

[Erik Sigra <freeciv@xxxxxxx>]

These new riverboats are cool :-)

They let you undertake unmanned colonization expeditions. Just take an
empty trireme and head for another continent. Sail up as far as you can
in every river you find. Hopefully you will find a hut on some river.
Enter it with your trireme. If you get a city or a settlers -
congratulations. You have just gained foothold on a new continent
without building a settler and risking it on a trireme. If you get some
other unit - use it to enter the huts you can't access from a river. If
you get no unit - keep searching with your trireme, unless the evil
barbarians took it.