[tex-hyphen] UTF-ization of hyphenation patterns

[Arthur Reutenauer]

> To clean up some mess in loading the patterns, it would be nice to go
> the other way around, and start from proper Unicode (UTF-8) patterns
> and let (pdf)TeX interpret UTF-8 patterns in its own way instead of
> both XeTeX and LuaTeX having to deal with some really weird encodings
> in patterns.

  Great!  Could we also try to get away from the naming mess and use
standards tags for languages?  The relevant document is IETF Best
Current Practice 47 (http://tools.ietf.org/html/bcp47) -- currently it's
RFC 4646 and 4647, but it's under revision.  It's already well on its
way, but some tags could be modified.  I can prepare the complete list
of tags for languages in language.dat

	Arthur