- new jam damage thresholds for guns - when a gun jams it can only take damage if its status is below the threshold

- modified damage calculation for jam damage
- modified cleaning point calculation for mercs
- natural dirt level of sectors now halved if the shooter is inside a building

git-svn-id: https://ja2svn.mooo.com/source/ja2/trunk/GameSource/ja2_v1.13/Build@8370 3b4a5df2-a311-0410-b5c6-a8a6f20db521

GameSettings.h

@@ -2355,6 +2355,8 @@ typedef struct
 	// Recoil modifiers
 	FLOAT fRecoilXModifierGun[GUN_TYPES_MAX];
 	FLOAT fRecoilYModifierGun[GUN_TYPES_MAX];
+	// Jam damage thresholds
+	UINT16 usJamDamageThresholdGun[GUN_TYPES_MAX];
 
 	// -------------- ARMOR MODIFIERS ----------------
 	FLOAT fCamoLBEoverVestModifier;