CoverArtCache - adding namespace prefix to the cache keys
WCoverMenu - composing path using QDir::filePath()
cosmetic fix - clarifying the filename of the default cover
cosmetic fix - inverting if statement
DlgTrackInfo - set the pixmapFound() signal&slot to use AutoConnection - it avoids running dlgtrackinfo in another thread
changes the showCoverArt config key to the [Library] section
cosmetic fix - code style