* lisp.h (toplevel): Add comment about using Lisp_Save_Value

* lisp.h (toplevel): Add comment about using Lisp_Save_Value
objects, related functions and macros.
(make_save_value): Adjust prototype.
(make_save_pointer): New prototype.
(SAFE_NALLOCA): Fix indentation.  Use make_save_pointer.
(SAFE_ALLOCA_LISP): Adjust make_save_value usage.
* alloc.c (format_save_value): Rename to make_save_value.
(make_save_pointer): New function.
(record_xmalloc): Use make_save_pointer.
* dired.c, editfns.c, fileio.c, font.c, gtkutil.c, lread.c:
* nsmenu.m, nsterm.m, xfns.c, xmenu.c, xselect.c, keymap.c:
Change users of make_save_value to make_save_pointer.
Likewise for format_save_value and make_save_value.