Track Info [Playlist] field: Add playlist name

For any selected track that is part of a playlist,
additional info about the list is now provided in
the [Playlist] field of the Track Info screen.

1) Asterisk indicates if playlist has been modified.
2) Playlist filename is visible, unless the current
playlist is *not* associated with a file on disk, in
which case the following will be shown instead:

- (Folder)    for unmodified folder playlists.
- (Dynamic)   for playlists that are neither associated
              with a playlist file, nor with a folder.

Change-Id: I9dcf7cbba4ac2e37b23413180a2b2bf4bbe5ee2a

apps/screens.h

@@ -24,6 +24,7 @@
 #include "config.h"
 #include "timefuncs.h"
 #include "metadata.h"
+#include "playlist.h"
 
 struct screen;
 
@@ -41,6 +42,9 @@ bool set_time_screen(const char* title, struct tm *tm, bool set_date);
 
 bool browse_id3(struct mp3entry *id3, int playlist_display_index, int playlist_amount,
                 struct tm *modified, int track_ct);
+bool browse_id3_ex(struct mp3entry *id3, struct playlist_info *playlist,
+                int playlist_display_index, int playlist_amount,
+                struct tm *modified, int track_ct);
 int  view_runtime(void);
 
 #ifdef HAVE_TOUCHSCREEN