Update miscellaneous files from upstream sources.

Update miscellaneous files from upstream sources.

This patch updates some miscellaneous files from their upstream
sources (thereby bringing in copyright date updates for some of those
files).

Tested for x86_64, including "make pdf".

	* manual/texinfo.tex: Update to version 2018-12-28.17 with
	trailing whitespace removed.
	* scripts/config.guess: Update to version 2019-01-01.
	* scripts/config.sub: Update to version 2019-01-01.
	* scripts/move-if-change: Update from gnulib.