Sync from coreutils.

Sync from coreutils.
Use "file name" when talking about file names, instead of "filename"
or "path", as per the GNU coding standards.

* MODULES.html.sh: mkdir-p renamed from makepath.
filenamecat renamed from path-concat.
* modules/filenamecat: Renamed from modules/path-concat.
(Files): filenamecat.h and filenamecat.c renamed from
path-concat.h and path-concat.c.
(configure.ac): gl_FILE_NAME_CONCAT, not gl_PATH_CONCAT.
(Include): filenamecat.h, not path-concat.h.
* modules/mkdir-p: Renamed from modules/makepath.
(Files): mkdir-p.h and mkdir-p.c renamed from makepath.h and makepath.c.
(configure.ac): gl_MKDIR_PARENTS, not gl_MAKEPATH.
(Include): mkdir-p.h, not makepath.h.
* lib/mkdir-p.c: Renamed from makepath.c.
(make_dir_parents): Renamed from make_path.  All callers changed.
* lib/mkdir-p.h: Likewise.  All includers changed.
* lib/filenamecat.c: Renamed from path-concat.c.
(file_name_concat): Renamed from path_concat.  All callers changed.
[TEST_FILE_NAME_CONCAT]: Renamed from TEST_PATH_CONCAT.
* lib/filenamecat.h: Likewise.  All includers changed.
* lib/acl.c: Don't use "path" or "filename" to mean "file name"
in comments or local variable names.
* lib/basename.c: Likewise.
* lib/canonicalize.c, canonicalize.h: Likewise.
* lib/dirname.c, dirname.h: Likewise.
* lib/euidaccess.c: Likewise.
* lib/exclude.c: Likewise
* lib/fnmatch_.h, fnmatch_loop.c: Likewise.
* lib/fsusage.c, fsuage.h: Likewise.
* lib/fts.c, fts_.h: Likewise.
* lib/getcwd.c: Likewise.
* lib/getloadavg.c: Likewise.
* lib/mkstemp.c: Likewise.
* lib/mountlist.c, mountlist.h: Likewise.
* lib/openat.c, openat.h: Likewise.
* lib/readlink-stub.c: Likewise.
* lib/readutmp.c, readutmp.h: Likewise.
* lib/rename.c: Likewise.
* lib/rmdir.c: Likewise.
* lib/same.c: Likewise.
* lib/savedir.c: Likewise.
* lib/stripslash.c: Likewise.
* lib/tempname.c: Likewise.
* lib/xreadlink.c: Likewise.
* lib/exclude.c (excluded_file_name): Renamed from excluded_filename.
All uses changed.
* lib/exclude.h: Likewise.
* m4/mkdir-p.m4: Renamed from makepath.m4.
(gl_MKDIR_PARENTS): Renamed from gl_MAKEPATH.  All uses changed.
Rename files from makepath.c to mkdir-p.c, and from
makepath.h to mkdir-p.h.
* m4/filenamecat.m4: Renamed from path-concat.m4.
(gl_FILE_NAME_CONCAT): Renamed from gl_PATH_CONCAT.  All uses changed.
Rename files from path-concat.c to filenamecat.c,
and from path-concat.h to filenamecat.h.
* m4/getcwd-path-max.m4: Don't use "path" or "filename" to mean
"file name" in local variables or comments.
* rename.m4: Likewise.

* lib/euidaccess.c (getuid, getgid, getuid, getegid)
[!defined _POSIX_VERSION]: Remove decls; not needed these days.
* lib/idcache.c (getpwuid, getpwnam, getgrgid, getgrnam)
[!defined _POSIX_VERSION]: Remove decls; not needed these days.
* lib/pathmax.h: Include <limits.h> unconditionally, since other
files have been getting away with it for years (MORE/BSD 4.3
is extinct now).
* lib/userspec.c (getpwnam, getgrnam, getgrgid)
[!defined _POSIX_VERSION]: Remove decls; not needed these days.

* lib/pathmax.h (_POSIX_PATH_MAX) [!defined _POSIX_PATH_MAX]:
Define to 256, not 255, as per modern POSIX.