levels: replace all {S,W,B}FALL textures

Replace all {S,W,B}FALL textures in the levels with their animated
equivalents, and remove {S,W,B}FALL from textures.cfg.

The {S,W,B}FALL were leftovers from when Freedoom had the goal of
being Boom-compatible instead of vanilla-compatible.

Also, rebuild these levels' nodes and reject tables with ZenNode.

lumps/textures/textures.cfg

@@ -1517,8 +1517,6 @@ SW2STONE        128     128
 
 #endif
 
-BFALL           64      128
-*   BFALL1      0       0
 BFALL1          64      128
 *   BFALL1      0       0
 BFALL2          64      128
@@ -1834,8 +1832,6 @@ WOODSKUL        64      128
 *   WALL40_1    0       0
 *   SW2_2       24      70
 ; Missing waterfall textures:
-WFALL           64      128
-*   WFALL1      0       0
 WFALL1          64      128
 *   WFALL1      0       0
 WFALL2          64      128
@@ -2263,9 +2259,6 @@ REDWALL1        128     128
 *   W15_5       64      0
 SHAWN2          64      128
 *   AG128_1     0       0
-; fraggle 23/7/2002: added static SFALL texture
-SFALL           64      128
-*   SFALL1      0       0
 SFALL1          64      128
 *   SFALL1      0       0
 SFALL2          64      128