Addition request: alsatian

[Frank Ellermann]

Michael Everson wrote:
 
> we should be able to add an annotation to specify this use of gsw-FR.

Apart from Doug's "comment" idea or my "add description in 639-3" idea
another possibility is to register variant "Alsatian" as proposed by
Stéphane, and immediately deprecate it in favour of "gsw-fr".  This is
on the border to a "registry hack", but within what RFC 4646 offers.

 Frank