[Freeciv-Dev] (PR#2586) class and legend data patch

["esr@xxxxxxxxxxx via RT" <rt@xxxxxxxxxxxxxx>]

As discussed on the freeciv-data list, this patch adds class attributes for 
all nations and legend attributes for most.  It adds a few more cities and
leaders, as well.

I considered splitting the Historical category into Historical and Regional,
but I think that is more likely to stir political argument than just having
one category.

This should be applied on top of my previous two data patches, the original
Barsoom patch and the corrections.
-- 
                <a href="http://www.tuxedo.org/~esr/";>Eric S. Raymond</a>