Patch for iso-639.def

[Daniel Yacob]

Greetings,

Thank you for incorporating the changes.  To be certain, for
the languages "Ge'ez", "Sidamo" and "Tigre" there are no
Alpha-2 definitions in ISO-639, only the Alpha-3 assignments
have been made.  I want to make sure there is no confusion
here.

The 2 characters codes shown in the patch are those I had
suggested earlier, they do not present conflicts with existing
ISO-639-2 codes.  Since the time of my first email I've
begun working with members of the ISO-639 committee to
create new Alpha-2 codes derived from the SIL language codes.

Accordingly some changes have come about, only Tigre is
impacted here where the Alpha-2 code becomes "bd".

For a complete table of these developing codes please visit:

  http://www.geez.org/iso639/

"Beja" is another language with an Alpha-3 code but not an
Alpha-2 code, you might like to add it.  The proposed Alpha-2
code is "bj".

Apologies if there has been any confusion over the status of
these codes.

cheers,

/Daniel