[Freeciv-Dev] Unique city names

[tkurppa <teemu@xxxxxxxxxx>]

This is (hopefully) the final version of unique city names -patch. 
It implements server side features, which prevent naming all cities of the
player with same name. See    
http://arch.freeciv.org/freeciv-dev-200111/msg00381.html
http://arch.freeciv.org/freeciv-dev-200111/msg00761.html
for previous discussion. 

The code has get some extra bloat compared to initial solution, as
I implemented different possible naming restrictions that came up during
discussion. Server variable 'citynames' is used to select one that
suits to one's taste. There are now 4 different modes:
0 - no restrictions (as it is now) 
1 - a city name has to be unique to player (default) 
2 - a city name has to be globally unique 
3 - a city name has to be globally unique, and players can't use names
that are among other players' default city names. 

I've tested it quite extensively, manually and with autogames. In my
tests I've usually used Catalan and Spanish nations, as they have some
overlap on their city names. So pathological cases of mode 3 should also
work correctly. 

Teemu Kurppa

citynames.diff
Description: Text document