Log Message:
audio/abcde: Drop MESSAGE and clarify DESCR

MESSAGE explained that the package, despite being "a frontend
command-line utility (actually, a shell script) that grabs tracks off
a CD, encodes them to ogg, mp3 or flac formats, and tags them, all in
one go." does not contain or depend on any encoders.  Explain this
surprising situation in DESCR, which should explain what the package
does, and give a parenthetical hint about encoders it might use.