Added OverrideCriticalFile option for specifying alternative crit file

Added code for preparing clearing map_update_event in queue.

Fixed a crash bug in message_str_game function when passing a negative
fileId value.

Corrected/edited some code.

artifacts/ddraw.ini

@@ -319,7 +319,7 @@ OverrideArtCacheSize=0
 ;Set to 2 to block all saving in combat
 SaveInCombatFix=1
 
-;Point at an ini file containing elevator data
+;Point to an ini file containing elevator data
 ;ElevatorsFile=Elevators.ini
 
 ;Uncomment and set a comma delimited list of numbers to use a custom xp table.
@@ -347,6 +347,8 @@ AdditionalWeaponAnims=1
 ;If the ExtraKillTypes option is enabled, this should be set to 3, with containing entries for any new types
 ;Must be non-zero to use the edit/get/reset_critical script functions
 OverrideCriticalTable=2
+;To change the path and filename of the critical table file, uncomment the next line
+;OverrideCriticalFile=CriticalOverrides.ini
 
 ;Set to 1 to get notification of karma changes in the notification window
 DisplayKarmaChanges=0
@@ -489,7 +491,7 @@ FastShotFix=1
 BoostScriptDialogLimit=0
 
 ;Allows you to edit the skill tables
-;Point the next line at an ini file containing the replacement skill data
+;Point the next line to an ini file containing the replacement skill data
 ;SkillsFile=Skills.ini
 
 ;To change the relationship between SPECIAL stats and derived stats, uncomment the next line