New ISO 639 codes in February/March

Small changes where made February the 5th (ISO 639-2), the 18th, the 28th and March the 5th (all ISO 639-3). gsw now includes Alsatian as a name in ISO 639-2 and ISO 639-3 and mly, muw and xst where split into new codes. I hope I didn't forget any changes.

File iso-639-3_Retirements_20080228.tab has a errorneous line break in line 69/70 which needs to be fixed and is actually encoded in Latin1 which I missed before.

Finally now these are the local versions:

+--------------------------+----------+
| Entity                   | Version  |
+--------------------------+----------+
| ISO 639-2                | 20080205 |
| ISO 639-3                | 20080218 |
| ISO 639-3 Name Index     | 20080305 |
| ISO 639-3 Macrolanguages | 20080228 |
| ISO 639-3 Retirements    | 20080228 |
+--------------------------+----------+