Most of this change is to boilerplate commentary such as license URLs.
This change was prompted by ftp://ftp.gnu.org's going-away party,
planned for November.  Change these FTP URLs to https://ftp.gnu.org
instead.  Make similar changes for URLs to other organizations moving
away from FTP.  Also, change HTTP to HTTPS for URLs to gnu.org and
fsf.org when this works, as this will further help defend against
man-in-the-middle attacks (for this part I omitted the MS-DOS and
MS-Windows sources and the test tarballs to keep the workload down).
HTTPS is not fully working to lists.gnu.org so I left those URLs alone
for now.

This incorporates:
2017-08-15 renameat: ensure declaration in <stdio.h> on NetBSD
2017-08-15 extensions: enable NetBSD specific extensions
2017-08-14 open: support O_CLOEXEC
2017-08-13 reallocarray: new module
* admin/merge-gnulib (AVOIDED_MODULES): Remove ‘open’, since
it now supports O_CLOEXEC and this simplifies Emacs.
* build-aux/config.guess, lib/fcntl.in.h, lib/stdio.in.h:
* lib/stdlib.in.h, m4/extensions.m4, m4/stdlib_h.m4:
Copy from Gnulib.
* lib/cloexec.c, lib/cloexec.h, lib/open.c:
* m4/mode_t.m4, m4/open-cloexec.m4, m4/open.m4:
New files, copied from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib-src/etags.c (O_CLOEXEC) [WINDOWSNT]:
Remove, as Gnulib does this for us.
* src/filelock.c (create_lock_file):
* src/sysdep.c (emacs_open, emacs_pipe):
Don’t worry about O_CLOEXEC == 0, as Gnulib no longer sets it to 0.

For the motivation behind this patch, please see Bug#28023 and:
http://emacshorrors.com/posts/make-temp-name.html
Although, given the recent changes to Tramp, the related security
problem in make-temp-file is already fixed, make-temp-file still has
several unnecessary system calls.  In the typical case on GNU/Linux,
this patch replaces 8 syscalls (symlink, open, close, readlinkat, uname,
getpid, unlink, umask) by 2 (open, close).
* admin/merge-gnulib (GNULIB_MODULES): Add tempname, now
that Emacs is using it directly.
* configure.ac (AUTO_DEPEND): Remove AC_SYS_LONG_FILE_NAMES;
no longer needed.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lisp/files.el (files--make-magic-temp-file): Rename from
make-temp-file.
(make-temp-file): Use make-temp-file-internal for
non-magic file names.
* src/fileio.c: Include tempname.h.
(make_temp_name_tbl, make_temp_name_count)
(make_temp_name_count_initialized_p, make_temp_name): Remove.
(Fmake_temp_file_internal): New function.
(Fmake_temp_name): Use it.
* src/filelock.c (get_boot_time): Use Fmake_temp_file_internal
instead of make_temp_name.

This incorporates:
2017-08-09 tempname: do not depend on secure_getenv
2017-08-08 extensions: add _OPENBSD_SOURCE
2017-08-06 manywarnings: Add support for C++
2017-08-06 warnings, manywarnings: Add support for multiple languages
* admin/merge-gnulib: Don't use m4/manywarnings-c++.m4.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/secure_getenv.c, m4/secure_getenv.m4: Remove.
* lib/tempname.c, m4/extensions.m4, m4/manywarnings.m4, m4/warnings.m4:
Copy from gnulib.

* admin/merge-gnulib (GNULIB_MODULES): Add d-type.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* m4/d-type.m4: New file, copied from gnulib.
* src/dired.c (DT_UNKNOWN, DT_DIR, DT_LINK)
[!HAVE_STRUCT_DIRENT_D_TYPE]: New constants.
(dirent_type): New function.
(file_name_completion): Use it, to avoid unnecessary calls to
stat-like functions on GNU/Linux and other platforms with d_type.
(file_name_completion_stat): Just follow the link; there is no
need to try first with AT_SYMLINK_NOFOLLOW since the directory
entry was already checked to exist.

This incorporates:
2017-07-23 Rename module 'strftime' to 'nstrftime'
* admin/merge-gnulib (GNULIB_MODULES): Add nstrftime, remove strftime.
* build-aux/config.guess: Copy from gnulib.
* lib/nstrftime.c: Rename from lib/strftime.c.
* m4/nstrftime.m4: Rename from m4/strftime.m4.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.