a few small changes

[Jim Meyering]

Install still accepted --preserve_context.  patch-4/7 removes it.
While looking at that, I noticed install.c was one of the
very few files in coreutils with forward declarations for
static functions.  Normally we put "main" at the end
and order callees before callers.  I've removed those
forward declarations (unnecessary duplication) and reordered
the functions to make them unnecessary.

There have been a few fixes in gnulib, including
a new syntax-check rule that catches doubled words,
(yes, there were a few here), so I've updated to the latest:

[PATCH 1/7] maint: remove doubled words in comments, e.g., s/to
[PATCH 2/7] maint: rename variables for clarity...
[PATCH 3/7] maint: reorder install.c to eliminate declarations of
[PATCH 4/7] maint: install: remove support for --preserve_context
[PATCH 5/7] doc: tweak NEWS
[PATCH 6/7] cfg.mk: remove useless semicolon and backslash
[PATCH 7/7] build: update gnulib submodule to latest