[freeciv-ai] definitely last version of active diplomats patch

["Per I. Mathisen" <per@xxxxxxxxxxx>]

This version cleans up all Mike's complaints, then cleans up even more,
and replaces the kludgy use of real_map_distance with real use of warmaps,
including in the bribery function, where we now not just consider adjacent
targets, but any target we can reach, up to and including ships in the
coastline!

You must be thinking, "this got to be slow". But it isn't! Since warmaps
are cached and we create them anyway in do_unit_goto(), the actual impact
is not even measurable with five seconds of inaccuracy.

Warmaps rock!!

Issues that can still be considered before inclusion:
 - "medium" difficulty unchanged. It should probably not have active
   diplomats. They are nasty.
 - Now that we are so good at bribing, we may want to keep more diplomats
   in defense. Tony's previous approach (never send a diplomat out on
   action unless we have one in defence), may actually be a good idea now.

Another issue:
 - We should _seriously_ upgrade our want to Courthouse now. That would be
   a good idea anyway (my calculations show them to be better than
   Marketplace in most situations). I'll look at that once Ross'
   ai_eval_buildings() cleanup hits cvs.

But:
Please don't complain about the incite algorithm. Once the code is in cvs,
it is much easier to test out new, experimental algorithms. I've tested
this one for many, many hours and it seems to work, so I don't want to
change it now.

I've attached a small savegame created in civworld, which demonstrates the
use of warmap bribery. Login as David Ben-Gurion and watch your diplomat
travel around the island by rail to snatch up the coastal destroyer.

Yours
Per

"I don't see why people are so upset about cloning sheep. American
television networks have been doing that to their audiences for years."
-- Jello Biafra

diplotest.sav.gz
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activediplomatsng4.diff
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