remove pointer to long conversions - part 3 of 3 (trunk only)

Remove some more code that forced pointers into a long int, and
vice versa where information could be lost (P64 platforms such as
WIN64 have a 64 bit pointer size, but a 32 bit long size.)

This 3rd part deals with region functions switching
some arguments from type genericptr_t to 'anything'.

Like the previous 2 parts, this needs to increment
 EDITLEVEL in patchlevel.h.

include/patchlevel.h

@@ -13,7 +13,7 @@
  * Incrementing EDITLEVEL can be used to force invalidation of old bones
  * and save files.
  */
-#define EDITLEVEL	35
+#define EDITLEVEL	36
 
 #define COPYRIGHT_BANNER_A \
 "NetHack, Copyright 1985-2006"

include/region.h

@@ -59,7 +59,7 @@ typedef struct {
 
   boolean visible;		/* Is the region visible ? */
   int glyph;			/* Which glyph to use if visible */
-  genericptr_t arg;		/* Optional user argument (Ex: strength of
+  anything arg;			/* Optional user argument (Ex: strength of
 				   force field, damage of a fire zone, ...*/
 } NhRegion;