(PR#12451) ai taxes

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=12451 >

> [per - Fri Mar 18 12:21:21 2005]:
> It seems code the AI relied upon has changed (cached perhaps?) so that it
> can no longer query income from player_get_expected_income() with various
> tax rates without running a total refresh on all cities first. Since that
> option is totally out of the question, I made a simplification. We now
> assume the entire civ is a single city, and distribute total trade
> according to tax rates within the AI code.

The new method doesn't count unit upkeep.
--
mateusz