Trade items spawn in cities.

[MikhailRyabov]

The bug with absence of many items has been solved, however the economic system of the world does not work properly. The cities too rarely spawn good armor, what is more, the rate of spawn is different for different countries, it might be connected to the level of prosperity of the city, but it grows too slowly, 258 day and the best armor I found in vlandian city shop was western mail. the best imperial armor was cavalry mail. the mechanism of appearance of top tier armor is either broken or too slow.