Fixing bug with XiphComment's tag - getting cover_art of OGG and FLAC files
CoverArtCacheTEST - cosmetic fixes
fixing CoverArtCacheTest::searchImage - it's no longer returning an empty coverLocation
fixing bug with FLAC file - read pictureList in order to try getting a cover anyway
CoverArtCacheTest::extractEmbeddedCover - add test to all supported file formats
fixing test/id3-test-data/readme.txt file