Make it possible to see how much money it would be needed to incite your city

[Corbeau-1]

Currently it is not possible. It's possible to see bribe cost of your unit, but not the price of a city. Funny for the enemy to have this information, but you don't.

[lmoureaux]

This is calculated by the function city_incite_cost in server/cityturn.{h,cpp}. Would need to move it to common then call it from the city dialog code. We may need to make the base_incite_cost and incite_improvement_factor variables part of the game.info structure so they get sent to the client (changing the network protocol). Another solution would be for the server to send the cost directly (also needs a protocol change).