throw away unused function (MediaLibrary::SortSongsByYear())

src/media_library.cpp

@@ -710,11 +710,6 @@ bool MediaLibrary::SearchConstraintsSorting::operator()(const SearchConstraints
 	return (result == 0 ? cmp(a.Album, b.Album) : result) < 0;
 }
 
-bool MediaLibrary::SortSongsByYear(Song *a, Song *b)
-{
-	return a->GetDate() < b->GetDate();
-}
-
 bool MediaLibrary::SortSongsByTrack(Song *a, Song *b)
 {
 	if (a->GetDisc() == b->GetDisc())

src/media_library.h

@@ -87,7 +87,6 @@ class MediaLibrary : public Screen<Window>
 		static void DisplayAlbums(const SearchConstraints &, void *, Menu<SearchConstraints> *);
 		
 		static bool SortSongsByTrack(MPD::Song *, MPD::Song *);
-		static bool SortSongsByYear(MPD::Song *, MPD::Song *);
 		
 		static bool hasTwoColumns;
 		static size_t itsLeftColWidth;