a pox on trailing white space

[Jim Meyering]

After looking at trim.c, I searched for all trailing blanks
in gnulib and found plenty:

  $ g grep -l '[        ]$'
  build-aux/gendocs.sh
  build-aux/texinfo.tex
  config/srclist-update
  doc/COPYING.LESSERv2
  doc/COPYING.LESSERv3
  doc/Copyright/assign.future.manual
  doc/Copyright/assign.manual
  doc/Copyright/request-assign.changes
  doc/Makefile
  doc/error.texi
  doc/gendocs_template
  doc/gendocs_template_min
  doc/gnulib.texi
  doc/gpl-2.0.texi
  doc/lgpl-2.1.texi
  doc/maintain.texi
  doc/posix-functions/chown.texi
  doc/regexprops-generic.texi
  doc/relocatable-maint.texi
  doc/standards.texi
  lib/argp-help.c
  lib/argp-parse.c
  lib/argz.c
  lib/git-merge-changelog.c
  lib/javacomp.h
  lib/round.c
  lib/trim.c
  m4/argz.m4
  m4/ldd.m4
  modules/unilbrk/u16-possible-linebreaks
  modules/unilbrk/u32-possible-linebreaks
  modules/unilbrk/u8-possible-linebreaks
  tests/test-argp-2.sh
  tests/test-round2.c
  tests/unictype/test-categ_and.c
  tests/unictype/test-categ_and_not.c
  top/maint.mk
  users.txt

If anyone objects to my removing all of them, speak now...