This patch updates various miscellaneous files from their upstream
sources.
Tested for x86_64, including "make pdf".
* manual/texinfo.tex: Update to version 2017-12-18.20 with
trailing whitespace removed.
* scripts/config.guess: Update to version 2017-12-17.
* scripts/config.sub: Update to version 2017-11-23.
* scripts/install-sh: Update to version 2017-09-23.17.
* scripts/move-if-change: Update to version 2017-09-13 06:45.