Modified cave floor terrain to look a bit rougher

(though less rough than the cave hills) so it actually looks like a
possible impediment to movement.  Further modification will probably
follow.

data/terrain-graphics.cfg

@@ -376,12 +376,11 @@
 #       >  B A S E   T E R R A I N S  <
 #
 
-#10% 3% 13% 7% 67%
-{TERRAIN_BASE_PROB  (Uu*,Uf)          cave/floor4		       10}
-{TERRAIN_BASE_PROB  (Uu*,Uf)          cave/floor3		       3}
-{TERRAIN_BASE_PROB  (Uu*,Uf)          cave/floor2		       15}
-{TERRAIN_BASE_PROB  (Uu*,Uf)          cave/floor		       10}
-{TERRAIN_BASE       (Uu*,Uf)          cave/floor1}
+{TERRAIN_BASE_PROB  (Uu*,Uf)          cave/floor2		       20}
+{TERRAIN_BASE_PROB  (Uu*,Uf)          cave/floor3		       25}
+{TERRAIN_BASE_PROB  (Uu*,Uf)          cave/floor4		       33}
+{TERRAIN_BASE_PROB  (Uu*,Uf)          cave/floor5		       50}
+{TERRAIN_BASE       (Uu*,Uf)          cave/floor6}
 
 {TERRAIN_BASE       Xu                cave/wall-rough}
 

data/terrain.cfg

@@ -658,7 +658,7 @@ editor_group=cave, rough
 [/terrain]
 
 [terrain]
-symbol_image=cave/floor
+symbol_image=cave/floor6
 id=cave
 name= _ "Cave"
 string=Uu