Support looping FLAC files

[ribbanya]

Apparently FLAC can store WAVE metadata, so it should be fairly simple to reuse the WAV parsing code to an extent in order to supporting looping FLACs.

I'll do some messing around with FLAC files and if it works out, I'll go ahead and implement this.

[Carldacious]

Sweet! Very interested if this can work! I was trying to figure out a way to transfer loop points added to a WAV with Wavosaur to FLAC, but as far as I could tell it was unsuccessful. Other than with Wavosaur or with m-overlay's debug menu, I was unable to see loop point metadata. I tried using mp3tag, but regardless of playing around with fields I could not get it to appear there in a form that was see-able or edit-able.

This will be perfect if we can get this up and running! If I can be of any help, let me know!