Update texinfo.tex, config.guess, config.sub from upstream.
This patch updates various miscellaneous files we take from upstream
GNU sources (texinfo.texi, config.guess, config.sub - various others
haven't changed upstream since we last updated them) to their current
upstream versions.
Tested x86_64.
* manual/texinfo.tex: Update to version 2013-11-26.10 with
trailing whitespace removed.
* scripts/config.guess: Update to version 2013-11-29.
* scripts/config.sub: Update to version 2013-10-01.