#23 some mp123 cleanups

[Ozkan Sezer]

The attached patch does the following:

• comments out some remnants of OSS variables,
• frees filedata right after ModPlug_Load() is called,
• opens the audio device only once, instead of opening and
  closing it per file, (without this it ends up with a
  device open failure when I feed lots of files to it),
• does some whitespace tidy-ups at a few places.