Add new preference: DefaultGroupOffsetSeconds to dictate the default sync bias on the machine when no group.ini is present (or if there is no SyncOffset field in said file).

- Generally Supports either ITG (9ms) or NULL (0ms).
- Alternatively, one could edit the preference manually to put a different value
- Name/Description probably worth ironing out

Themes/_fallback/Languages/en.ini

@@ -531,6 +531,7 @@ Transfer Edits to USB=Transfer Edits to USB
 Transfer Edits from USB=Transfer Edits from USB
 UseUnlockSystem=Enable or disable the unlock system.
 VisualDelaySeconds=Calibrate display lag.
+DefaultGroupOffsetSeconds=Change the Default Sync Bias
 Vsync=Cap your frame rate your display's refresh rate.  This option only has an effect when the Display Mode is set to &oq;Full Screen&cq;.
 WideScreen16_9=Enable widescreen display.
 WideScreen16_10=Enable widescreen display.
@@ -1308,6 +1309,7 @@ Undo=Undo
 UseUnlockSystem=Unlock System
 View steps data=View Steps Data
 VisualDelaySeconds=Visual Delay
+DefaultGroupOffsetSeconds=Default Group Offset
 Voltage=Voltage
 Vsync=Wait For Vsync
 Warps=Warps

Themes/_fallback/metrics.ini

@@ -3067,7 +3067,7 @@ Line22="conf,EventMode"
 Fallback="ScreenOptionsServiceChild"
 NextScreen="ScreenOptionsService"
 PrevScreen="ScreenOptionsService"
-LineNames="1,2,3,RefreshRate,FSType,4,5,6,7,8,9,10,11,13,FNR,14,17,18,19,20,21"
+LineNames="1,2,3,RefreshRate,FSType,4,5,6,7,8,9,10,11,13,FNR,14,17,18,19,20,21,22"
 Line1="lua,ConfDisplayMode()"
 Line2="lua,ConfAspectRatio()"
 Line3="lua,ConfDisplayResolution()"
@@ -3092,7 +3092,8 @@ Line17="conf,SoundVolume"
 Line18="conf,EnableAttackSounds"
 Line19="conf,EnableMineHitSound"
 Line20="conf,VisualDelaySeconds"
-Line21="conf,RateModPreservesPitch"
+Line21="conf,DefaultGroupOffsetSeconds"
+Line22="conf,RateModPreservesPitch",
 
 [ScreenOptionsAdvanced]
 Fallback="ScreenOptionsServiceChild"