* lib/strerror.c: Include <string.h> always, to test interface,
and to remove the need for the dummy.
Include intprops.h to compute width instead of doing it ourselves
and missing a CHAR_BIT declaration, which broke tar 1.19 on Solaris 8.
(strerror): Define it to return NULL if there's no system strerror.
(rpl_strerror): Use INT_STRLEN_BOUND to compute bound.
Omit !HAVE_STRERROR code. We don't need to worry about supporting
ancient pre-strerror Unix systems well any more. Saying "unknown
system error" is enough.
* lib/string.in.h (strerror): Simplify the ifdef to reflect the
simpler strerror.c implementation.
* m4/strerror.m4 (gl_FUNC_STRERROR_SEPARATE, gl_PREREQ_STDERROR):
Simplify the tests to reflect the simpler strerror implementation.
* modules/strerror (Depends-on): Add intprops.
* modules/alloca, modules/atexit, modules/memmove:
Now public domain, not GPL.
* modules/dup2, modules/getpagesize, modules/malloc, modules/memset:
* modules/realloc, modules/strerror, modules/strtod:
Now LGPL, not GPL.
