[uf-new] renaming work-title to fn in hAudio (was: An argument against 'fn' in hAudio)

[Manu Sporny]

Scott's argument was the final nail in the 'work-title' coffin. Work
title has been changed to 'fn' and is reflected on the wiki:

http://microformats.org/wiki/audio-info-proposal#Schema

http://microformats.org/wiki/audio-info-proposal#Formatted_Name

-- manu