Add setting to control whether trains can crash with other companies'.

src/table/settings.ini

@@ -1142,6 +1142,15 @@ strhelp  = STR_CONFIG_SETTING_PLANE_CRASHES_HELPTEXT
 strval   = STR_CONFIG_SETTING_PLANE_CRASHES_NONE
 cat      = SC_BASIC
 
+[SDT_BOOL]
+base     = GameSettings
+var      = vehicle.no_train_crash_other_company
+def      = false
+str      = STR_CONFIG_SETTING_NO_TRAIN_CRASH_OTHER_COMPANY
+strhelp  = STR_CONFIG_SETTING_NO_TRAIN_CRASH_OTHER_COMPANY_HELPTEXT
+extver   = SlXvFeatureTest(XSLFTO_AND, XSLFI_INFRA_SHARING)
+patxname = ""infra_sharing.vehicle.no_train_crash_other_company""
+
 ; station.join_stations
 [SDT_NULL]
 length   = 1