New rail terrain type.

Has no effect on current units (may want to define values for UI purposes

changelog

@@ -36,6 +36,8 @@ Version 1.11.0-svn:
    * Deprecated flowers (Ggf) and Volcano (Qv) removed - use Gg^Efm and Mv
      respectively
    * Fix bridge/rail transitions to each other
+   * Add new rail terrain type; no existing unit can move on it, so their
+     move/defense values are unchanged
  * Unit changes and balancing:
    * New extra_define ENABLE_WOLF_ADVANCEMENT to optionally enable Wolves
      advancement to Great Wolves and Direwolves

data/core/terrain.cfg

@@ -931,8 +931,8 @@
     id=rails
     name= _ "Mine Rail"
     string=^Br|
-    aliasof=_bas
-    mvt_alias=Gt
+    aliasof=_bas,Rt
+    mvt_alias=Gt,Rt
     submerge=0
     unit_height_adjust=22
     editor_group=cave
@@ -943,8 +943,8 @@
     id=railsdiag1
     name= _ "Mine Rail"
     string=^Br/
-    aliasof=_bas
-    mvt_alias=Gt
+    aliasof=_bas,Rt
+    mvt_alias=Gt,Rt
     submerge=0
     unit_height_adjust=22
     editor_group=cave
@@ -955,8 +955,8 @@
     id=railsdiag2
     name= _ "Mine Rail"
     string=^Br\
-    aliasof=_bas
-    mvt_alias=Gt
+    aliasof=_bas,Rt
+    mvt_alias=Gt,Rt
     submerge=0
     unit_height_adjust=22
     editor_group=cave
@@ -2158,3 +2158,10 @@
     string=Qt       # wmllint: ignore
     hidden=yes
 [/terrain_type]
+[terrain_type]
+    symbol_image=void/void
+    id=rails
+    name= _ "Rails"
+    string=Rt      # wmllint: ignore
+    hidden=yes
+[/terrain_type]