proposal: Specify the use of `lang` for transliterated names

see: http://tools.ietf.org/html/bcp47#section-2.2.3 (esp. all the stuff around "script")
see: http://en.wikipedia.org/wiki/Romanization
see: http://en.wikipedia.org/wiki/ISO_15924
see: http://www.unicode.org/iso15924/iso15924-codes.html
Additional specification of a catch-all name form transliteration case

When the original language is not known, what do you put for the
transliterated name form script lang?  This represents my best guess.
Adjusting to the 'und' and 'und-' prefixes suggested by Barry
Merge pull request #271 from jdsumsion/transliterated-name-forms

proposal: Transliterated name forms