[Freeciv-Dev] (PR#13434) map size not dependant on number of players

["Peter Schaefer" <peter.schaefer@xxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=13434 >

Players frequently end up with maps that are too big, because someone
leaves after launch.

Suggestion:
There should be an option landppl, which if set, determines the number
of land tiles each player has.

map geometry could be calculated as 
map_tiles= landppl/(0.01*server_option_landmass);
rt= sqrt(landmass_in_tiles);
s= sqrt(12);
x= (int)(rt*4.0/s);
y= (int)(rt*3.0/s)+(map_has_poles?4:0);