[luatex] setting lccode "automatically"

[Arthur Reutenauer]

> .. correct, you need a per-language table, which (as far as I know)
> does not actually exist.

  It does, it's SpecialCasing.txt in the Unicode Character Database
(http://www.unicode.org/Public/6.0.0/ucd/SpecialCasing.txt); see
sections 3.13 and 5.18 of the Unicode Standard for more details
(http://www.unicode.org/versions/Unicode6.0.0/{ch03,ch05}.pdf).

  It actually has much more information than language-specific casing
exceptions, of which there are rather few (mostly for Turkish and Azeri,
and Lithuanian).

	Arthur