* lib/getaddrinfo.c (getnameinfo): Use new lightweight uinttostr,

* lib/getaddrinfo.c (getnameinfo): Use new lightweight uinttostr,
in place of snprintf.

* modules/inttostr (Files): Add lib/uinttostr.c.
* lib/uinttostr.c (inttostr): New file/function.
* lib/inttostr.h (uinttostr): Declare.
* m4/inttostr.m4: Add AC_LIBOBJ([uinttostr]).
* MODULES.html.sh (Numeric conversion functions <stdlib.h>):
Add uinttostr.
* modules/getaddrinfo (Depends-on): Remove snprintf.  Add inttostr.