Initial support for embedded cue sheets found in flac files

So far only seekpoints are supported, so no proper tagging yet
except for track number and track length.
Tagging should be done by parsing the cue sheet which
is often embedded as vorbis comment in flac files.
Furthermore the pathname should be configurable like "%A - %t - %T",
where %A means Artist, %t track number and %T Title or so.

src/update.c

@@ -505,7 +505,7 @@ update_regular_file(struct directory *directory,
 			}
 		}
 
-		if (no_container == true)
+		if (no_container)
 		{
 			struct song *song = songvec_find(&directory->songs, name);