idz, idac, swdc: added FFB centering spring feature

dist/idac/segatools.ini

@@ -29,7 +29,7 @@ enable=1
 ; If you disable netenv then you must set this to your LAN's IP subnet, and
 ; that subnet must start with 192.168. Set it to your LAN's subnet if you 
 ; want to play head-to-head using netenv=1.
-subnet=192.168.100.0
+subnet=192.168.158.0
 
 ; Override the keychip's region code. Most games seem to pay attention to the
 ; DS EEPROM region code and not the keychip region code, and this seems to be
@@ -174,3 +174,8 @@ gear6=18
 ; (Needed when using DirectInput for the Dualshock 4 for example)
 reverseAccelAxis=0
 reverseBrakeAxis=0
+
+; Force feedback settings.
+; Strength of the force feedback spring effect in percent. Possible values
+; are 0-100.
+centerSpringStrength=30

dist/idz/segatools.ini

@@ -173,3 +173,8 @@ gear6=18
 ; (Needed when using DirectInput for the Dualshock 4 for example)
 reverseAccelAxis=0
 reverseBrakeAxis=0
+
+; Force feedback settings.
+; Strength of the force feedback spring effect in percent. Possible values
+; are 0-100.
+centerSpringStrength=30

dist/swdc/segatools.ini

@@ -133,3 +133,8 @@ wheelGreen=10
 ; (Needed when using DirectInput for the Dualshock 4 for example)
 reverseAccelAxis=0
 reverseBrakeAxis=0
+
+; Force feedback settings.
+; Strength of the force feedback spring effect in percent. Possible values
+; are 0-100.
+centerSpringStrength=30