Add setting to control RV re-routing on road layout change

Default to road removal only
This is due to poor performance with many RVs when town growth is
continually adding to the road layout

src/table/settings.ini

@@ -1293,6 +1293,21 @@ var      = pf.roadveh_queue
 def      = true
 cat      = SC_EXPERT
 
+[SDT_VAR]
+base     = GameSettings
+var      = pf.reroute_rv_on_layout_change
+type     = SLE_UINT8
+guiflags = SGF_MULTISTRING
+def      = 1
+min      = 0
+max      = 2
+interval = 1
+str      = STR_CONFIG_SETTING_REROUTE_RV_ON_LAYOUT_CHANGE
+strhelp  = STR_CONFIG_SETTING_REROUTE_RV_ON_LAYOUT_CHANGE_HELPTEXT
+strval   = STR_CONFIG_SETTING_REROUTE_RV_ON_LAYOUT_CHANGE_NO
+cat      = SC_ADVANCED
+patxname = ""pf.reroute_rv_on_layout_change""
+
 [SDT_BOOL]
 base     = GameSettings
 var      = pf.new_pathfinding_all