mutagen.id3 needs: * Detect tags in non-beginning locations, particularly if multiple separate version tags exist at the beginning of the file * Perhaps implement tag merging - "intelligently" merge information from all known tag formats * Some test cleanup mutagen.apev2 needs: * General cleanup to fit the basic structure of the rest of Mutagen. Profile Hotspots: * __determine_bpi takes 84% of TMP3,TEasyID3; BitPaddedInt takes 46%. * OggPage.replace takes 43% of Ogg tests; OggPage.write takes 25%. * insert_bytes/delete_bytes is still a hotspot but is much faster.