Update miscellaneous files from upstream sources.

This patch updates texinfo.tex and various miscellaneous scripts to
their latest upstream versions.  (There may be another update in early
January to bring in 2017 copyright dates, if the upstream versions get
updated with such dates promptly.)

Tested for x86_64.

	* manual/texinfo.tex: Update to version 2016-09-18.18 with
	trailing whitespace removed.
	* scripts/config.guess: Update to version 2016-10-02.
	* scripts/config.sub: Update to version 2016-11-19.
	* scripts/install-sh: Update to version 2016-01-11.22.
	* scripts/mkinstalldirs: Update to version 2016-01-11.22.
	* scripts/move-if-change: Update to version 2016-01-11 22:04.