libsaria: Tracks remove themselves from the list

This is mostly for when a library path is removed from the list.  Tracks
all remove themselves when destroyed, and then the library can be
refreshed.

include/libsaria/library.h

@@ -39,6 +39,7 @@ namespace libsaria
 		void for_each_path(void (*)(struct PathInfo &));
 
 		void list_track(libsaria::Track *);
+		void unlist_track(libsaria::Track *);
 		unsigned int size();
 		void filter(string &text);
 		bool is_visible(sid_t &);

include/libsaria/track.h

@@ -32,6 +32,7 @@ namespace libsaria
 
 			string *artist_lc;
 			string *album_lc;
+			bool needs_cleanup;
 			void make_lenstr();
 			void do_bookkeeping();
 

libsaria/library/list/list.cpp

@@ -24,6 +24,11 @@ namespace libsaria
 		track_list.push_back(track);
 	}
 
+	void library::unlist_track(libsaria::Track *track)
+	{
+		track_list.remove(track);
+	}
+
 	void library::sort_list()
 	{
 		track_list.sort(compare_tracks);

libsaria/track/track.cpp

@@ -13,6 +13,7 @@ namespace libsaria
 
 	Track::Track()
 	{
+		needs_cleanup = false;
 	}
 
 	Track::Track(string file, sid_t sid)
@@ -69,6 +70,8 @@ namespace libsaria
 
 	Track::~Track()
 	{
+		if (needs_cleanup)
+			libsaria::library::unlist_track(this);
 	}
 
 	void Track::do_bookkeeping()
@@ -77,6 +80,7 @@ namespace libsaria
 		album_lc = lowercase(album);
 		libsaria::index::add_track(this);
 		libsaria::library::list_track(this);
+		needs_cleanup = true;
 	}
 
 	void Track::save(OutFile &out)