Bug#800802: progress

[Daniel Pocock]

Issue (c), warnings about cuesheets from mkcue, may have been caused by
another bug in the checkflac script.  The line

FLACID=`flactag --discid $FILENAME | cut -d':' -f 2| cut -d' ' -f 2`

sets an empty $FLACID if the $FILENAME contains a space.  It should be
wrapped in double quotes.  I've fixed it in upstream commit
346d0ad569d7f6bf0a8232975712a42991a5650c

After fixing the checkflac script, I ran it against the same CD and the
disc IDs match.

I've also addressed issue (a) in the same commit, the checkflac output
now puts the word INVALID next to the disc ID from the FLAC file so it
is clear which disc ID should be removed from MusicBrainz.

While the disc ID is valid, the mkcue cuesheets don't contain pre-gap.
It doesn't appear to need pre-gap for calculating disc ID, but some
people may want their collection to be perfect, so they can reconstruct
the original CD from the FLAC.  Maybe the checkflac script should also
do a check to see if pre-gap information is missing and display a
different error for that?