GNU gettext and a couple of gnulib modules need only half of the 'dirname-lgpl'
module, namely essentially the 'basename' equivalent function (now called
'last_component').

In order to minimize dependencies, let me split this out into a separate
module.

So, 'dirname-lgpl' now depends on 'basename-lgpl'.

Also, let me enhance the documentation of function 'last_component'.
In particular, the documentation should state
  - what is the return value in case of a trailing slash,
  - why it is called 'last_component' and not 'basename',
  - what is the different w.r.t. glibc 'basename'.


2020-07-05  Bruno Haible  <bruno@clisp.org>

	mkancesdirs: Trim module dependencies.
	* lib/mkancesdirs.c: Include filename.h instead of dirname.h.
	* modules/mkancesdirs (Depends-on): Remove dirname-lgpl. Add filename.

2020-07-05  Bruno Haible  <bruno@clisp.org>

	getprogname: Trim module dependencies.
	* lib/getprogname.c: Include basename-lgpl.h instead of dirname.h.
	* modules/getprogname (Depends-on): Remove dirname-lgpl. Add
	basename-lgpl.

2020-07-05  Bruno Haible  <bruno@clisp.org>

	filenamecat-lgpl: Trim module dependencies.
	* lib/filenamecat-lgpl.c: Include basename-lgpl.h, filename.h instead of
	dirname.h.
	* modules/filenamecat-lgpl (Depends-on): Remove dirname-lgpl. Add
	basename-lgpl, filename.

2020-07-05  Bruno Haible  <bruno@clisp.org>

	backupfile, backup-rename: Trim module dependencies.
	* lib/backupfile.c: Include basename-lgpl.h instead of dirname.h.
	* modules/backupfile (Depends-on): Remove dirname-lgpl. Add
	basename-lgpl.
	* modules/backup-rename (Depends-on): Likewise.

2020-07-05  Bruno Haible  <bruno@clisp.org>

	argp: Trim module dependencies.
	* lib/argp-namefrob.h: Include basename-lgpl.h instead of dirname.h.
	* modules/argp (Depends-on): Remove dirname-lgpl. Add basename-lgpl.

2020-07-05  Bruno Haible  <bruno@clisp.org>

	basename-lgpl: New module.
	* lib/basename-lgpl.h: New file, based on lib/dirname.h and
	lib/basename-lgpl.c.
	* lib/basename-lgpl.c: Include basename-lgpl.h, not dirname.h. Include
	<stdbool.h>, filename.h.
	(last_component): Rename a local variable.
	* lib/dirname.h: Include basename-lgpl.h.
	(DOUBLE_SLASH_IS_DISTINCT_ROOT): Remove macro.
	(last_component, base_len): Remove declarations.
	* modules/basename-lgpl: New file.
	* modules/dirname-lgpl (Files): Remove lib/basename-lgpl.c.
	(Depends-on): Add basename-lgpl. Remove double-slash-root.
	(Makefile.am): Don't compile basename-lgpl.c.
	* doc/posix-functions/basename.texi: Mention the module 'basename-lgpl',
	not 'dirname'.

2020-07-05  Bruno Haible  <bruno@clisp.org>

	dirname, dirname-lgpl: Simplify.
	* m4/dirname.m4: Remove file.
	* modules/dirname (configure.ac): Don't invoke gl_DIRNAME.
	* modules/dirname-lgpl (Files): Remove m4/dirname.m4.
	(configure.ac): Don't invoke gl_DIRNAME_LGPL.