[freeciv-ai] AI tree

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

I have put the remaining big AI patches into a cvs tree in order to avoid
bitrot and as a way to give all of them proper testing in preparation for
later cvs inclusion.

Check out in freeciv ftp, the file massiveai2.diff.gz, which contains
 - A final cleanup of the bodyguard code, by myself
 - Active AI diplomats, by myself and Gregory Berkolaiko
   <Gregory.Berkolaiko@xxxxxxxxxxxx>
 - AI support for flying units, by Gregory Berkolaiko
   <Gregory.Berkolaiko@xxxxxxxxxxxx>
 - AI hitpoints recovery patch, by Jordi Negrevernis i Font
   <jorneg@xxxxxxxxxxx>

It also contains a number of other cleanups throughout the code:
 - Fixed a number of compile warnings in flying AI code.
 - Change defaults for coinage, courthouse, wall, SAM and coastal.
   Now coinage is TRADE_WEIGHTING want only, a kind of fallback.
   SAM trumps coinage, wall trumps SAM and coinage, while coastal
   trump them all three, and all just barely. Courthouse now
   doesn't calculate with a value where corruption has been
   deducted (assume continued existence of problem you solve,
   very bad).
 - Fixed bug whereas distances were thought 3x the real length
   because we now use warmaps.
 - Stop requiring barracks for offensive diplomats.
 - Remove braindead and broken default danger code.
 - Remove dumb check in enemies_at() which presumed that enemy
   cities are dangerous, even if empty. This didn't work well
   for sea or air units, making them stop early or even goto
   flip flop for no reason.
 - AI will now rather build Lighthouse or Unit Nations instead
   of more coinage
 - Don't bribe units that aren't a threat unless we have lots
   and lots gold, and even then don't bribe settlers
 - Medium difficulty AI won't use diplomats
 - Diplomats now stay and defend at urgency, not grave danger

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