Make sure temporary FIFO is removed upon SIGINT

[ FIXED ]  Leftover FIFO if a user invokes SIGINT before an operation
           has started
Allow ReplayGain logging to display directories

[ FIXED ]  Specifying using a delimiter with a '.flac' extension
           since ReplayGain will use directories instead of FLAC
           files.  Instead, use a more unique delimiter to key off of