[tex-hyphen] Bringing luatex-specific part of hyph-utf8 up-to-date

[Arthur Reutenauer]

> Off-topic ... I recall Frank (or someone from LaTeX) saying that it's
> not a good practice to use \documentclass{minimal} in general for test
> documents

  I actually use it in Polyglossia for testing features such as
hyphenation and \date in the several languages :-)  For this kind of
unit testing it's actually very useful, because I intentionally
disregard the document structure.

	Arthur