Replaced eco disaster icons with ones with more sensible color schemes
(warm colors for warming, cold for winter) by GriffonSpade.

See patch #4827


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25247 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Only reduce fractional movement points to lowest terms for display when
talking about rulesets and unit types in the abstract; when talking
about a specific unit, don't reduce, to avoid confusing changes as a
unit moves.

Requested by Marko Lindqvist (cazfi@gna).

See gna bug #22194.

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25249 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Sanity check move_fragments and igter_cost on ruleset load.

Suggested by Emmet Hikory (persia@gna).

See gna patch #4834.

git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25250 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Civil war related AI callback API changes
- Added parameter telling the created player to split_by_civil_war
- Added callback created_by_civil_war, called for created player 

See patch #4829


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@25253 a0f10bec-cc02-0410-94fc-a9cfff90b4cd