New option AI_TACTICAL_RETREAT (false by default) controls tactical enemy retreat from battle.

Moved options AI_YELLOW_FLANKING, AI_EXTRA_SUPPRESSION, AI_NEW_MORALE and AI_BETTER_COVER to [Tactical AI Settings]
AI_NEW_MORALE:
- zombies always have high morale
- always low morale when soldier is blinded
- neutrals always have low morale even if they have guns, so they don't run into the heat of battle
- prevent hopeless morale when not under attack
UpdateAniTiles: also check EXPLOSV_CREATUREGAS (from merc05's fixes)

git-svn-id: https://ja2svn.mooo.com/source/ja2/trunk/GameSource/ja2_v1.13/Build@8721 3b4a5df2-a311-0410-b5c6-a8a6f20db521

GameSettings.h

@@ -1536,6 +1536,9 @@ typedef struct
 	UINT8 ubAPSharedAmongPassengersAndVehicleMode;
 	UINT8 ubAPSharedAmongPassengersAndVehicleScale;
 
+	// sevenfm: AI settings
+	BOOLEAN fAITacticalRetreat;
+
 } GAME_EXTERNAL_OPTIONS;
 
 typedef struct