remove pointer to long conversions - part 1 of 3 (trunk only)

P64 (Win64) has a 64 bit pointer size, but a 32 bit long size.
Remove some code that forced pointers into a long int, and
vice versa where information could be lost.

This part deals with light source functions and their
arguments mostly, and switches some arguments
from type genericptr_t to 'anything'.

include/wintype.h

@@ -11,6 +11,7 @@ typedef int winid;		/* a window identifier */
 typedef union any {
     genericptr_t a_void;
     struct obj *a_obj;
+    struct monst *a_monst;
     int  a_int;
     char a_char;
     schar a_schar;