Adding other audio formats to Blorb

[vaporware (Tara McGrew)]

@Draconis

Out of those three formats, the most practical for IF purposes is MP3. Historically, Blorb didn’t support MP3 because of patent concerns. But those patents expired almost a decade ago now (in the US; in the EU it’s almost two decades), so this should no longer be an obstacle.

FWIW, AAC is also widely supported and the patents on its most common variants have also expired.