pointer formatting (trunk only)

Hide pointer formatting in alloc.c by eliminating the need for callers
to know how big a buffer is required.  I generally prefer the caller to
pass in its own buffer for this sort of thing, but in this case the usage
is almost entirely for debugging so using static buffers results in less
clutter in the rest of the code.

include/extern.h

@@ -12,7 +12,7 @@
 #if 0
 E long *FDECL(alloc, (unsigned int));
 #endif
-E char *FDECL(fmt_ptr, (const genericptr,char *));
+E char *FDECL(fmt_ptr, (const genericptr));
 
 /* This next pre-processor directive covers almost the entire file,
  * interrupted only occasionally to pick up specific functions as needed. */