Fix hanging, chasm stone, and plank bridge elevations

The N-S hanging bridge variant does not need an elevation shift, and
all diagonal variants of the other two were missing their own.

changelog

@@ -13,6 +13,10 @@ Version 1.12.4+dev:
    * Fix scenario ending to early for players that are defeated if there are
      still players fighting and victory_when_enemies_defeated=no.
    * Fix 'enemies defated' event causing OOS error in mp scenarios.
+ * Terrains:
+   * Removed unit elevation from N-S hanging bridges
+   * Added unit elevation to NW-SE and SW-NE stone chasm bridges
+   * Added unit elevation to NW-SE and SW-NE plank bridges
  * User interface:
    * Force uniform font rendering settings across X11 and Apple OS X, avoiding
      color glitches resulting from incorrect applications of subpixel hinting

data/core/terrain.cfg

@@ -2095,7 +2095,6 @@ For those who go by land or sea, a bridge is the best of both worlds — for gam
     string=^Bh|
     default_base=Qxu
     aliasof=_bas, Gt
-    unit_height_adjust=20
     editor_group=bridge, cave
 [/terrain_type]
 
@@ -2108,6 +2107,7 @@ For those who go by land or sea, a bridge is the best of both worlds — for gam
     string=^Bcx\
     default_base=Qxu
     aliasof=_bas, Gt
+    unit_height_adjust=22
     editor_group=bridge, cave
     hide_help=yes
 [/terrain_type]
@@ -2119,6 +2119,7 @@ For those who go by land or sea, a bridge is the best of both worlds — for gam
     string=^Bcx/
     default_base=Qxu
     aliasof=_bas, Gt
+    unit_height_adjust=22
     editor_group=bridge, cave
     hide_help=yes
 [/terrain_type]
@@ -2142,6 +2143,7 @@ For those who go by land or sea, a bridge is the best of both worlds — for gam
     string=^Bp\
     default_base=Qxu
     aliasof=_bas, Gt
+    unit_height_adjust=22
     editor_group=bridge, cave
     hide_help=yes
 [/terrain_type]
@@ -2153,6 +2155,7 @@ For those who go by land or sea, a bridge is the best of both worlds — for gam
     string=^Bp/
     default_base=Qxu
     aliasof=_bas, Gt
+    unit_height_adjust=22
     editor_group=bridge, cave
     hide_help=yes
 [/terrain_type]