Shuffle maintainer-specific rules.

Shuffle maintainer-specific rules.

* Makefile.am (maintainer-check-tests): Delete.
(autom4te-update): Move...
* cfg.mk (autom4te-update): ...here.
(fetch): Depend on autom4te-update.  Split...
(gnulib-update): ...into new rule.  Import move-if-change from
gnulib.
* maint.mk (maintainer-distcheck): Absorb former maintainer-check
rule.
* build-aux/move-if-change: New file, undistributed.
* .gitattributes: Handle new upstream file.
* .gitignore: Ignore maintainer cruft.
* HACKING: Update maintainer instructions.
* build-aux/config.guess: Update from upstream.
* build-aux/config.sub: Likewise.
* build-aux/gendocs.sh: Likewise.
* build-aux/texinfo.tex: Likewise.
* doc/gendocs_template: Likewise.
* doc/standards.texi: Likewise.

Signed-off-by: Eric Blake <ebb9@byu.net>