Add range start and end properties in milliseconds into mpd_song

Range `start` and `end` values in `mpd_song` is stored in seconds only,
which makes range times in `ProxySong` truncated to seconds and leads to
precision loss on satellite cue track range times.

This commit adds `start_ms` and `end_ms` properties to store range start
and end times in milliseconds, and corresponding functions to access
them: `mpd_song_get_start_ms`, `mpd_song_get_end_ms`. The values are
parsed from float time values returned by mpd server.

include/mpd/song.h

@@ -137,6 +137,14 @@ mpd_pure
 unsigned
 mpd_song_get_start(const struct mpd_song *song);
 
+/**
+ * Returns the start of the virtual song within the physical file in
+ * milliseconds.
+ */
+mpd_pure
+unsigned
+mpd_song_get_start_ms(const struct mpd_song *song);
+
 /**
  * Returns the end of the virtual song within the physical file in
  * seconds. 0 means that the physical song file is played to the end.
@@ -147,6 +155,14 @@ mpd_pure
 unsigned
 mpd_song_get_end(const struct mpd_song *song);
 
+/**
+ * Returns the end of the virtual song within the physical file in
+ * milliseconds. 0 means that the physical song file is played to the end.
+ */
+mpd_pure
+unsigned
+mpd_song_get_end_ms(const struct mpd_song *song);
+
 /**
  * @return the POSIX UTC time stamp of the last modification, or 0 if
  * that is unknown

libmpdclient.ld

@@ -366,7 +366,9 @@ global:
 	mpd_song_get_duration;
 	mpd_song_get_duration_ms;
 	mpd_song_get_start;
+	mpd_song_get_start_ms;
 	mpd_song_get_end;
+	mpd_song_get_end_ms;
 	mpd_song_get_last_modified;
 	mpd_song_set_pos;
 	mpd_song_get_pos;

src/song.c

@@ -78,13 +78,26 @@ struct mpd_song {
 	 */
 	unsigned start;
 
+	/**
+	 * Start of the virtual song within the physical file in
+	 * milliseconds.
+	 */
+	unsigned start_ms;
+
 	/**
 	 * End of the virtual song within the physical file in
 	 * seconds.  Zero means that the physical song file is
 	 * played to the end.
 	 */
 	unsigned end;
 
+	/**
+	 * End of the virtual song within the physical file in
+	 * milliseconds.  Zero means that the physical song
+	 * file is played to the end.
+	 */
+	unsigned end_ms;
+
 	/**
 	 * The POSIX UTC time stamp of the last modification, or 0 if
 	 * that is unknown.
@@ -147,7 +160,9 @@ mpd_song_new(const char *uri)
 	song->duration = 0;
 	song->duration_ms = 0;
 	song->start = 0;
+	song->start_ms = 0;
 	song->end = 0;
+	song->end_ms = 0;
 	song->last_modified = 0;
 	song->pos = 0;
 	song->id = 0;
@@ -230,7 +245,9 @@ mpd_song_dup(const struct mpd_song *song)
 	ret->duration = song->duration;
 	ret->duration_ms = song->duration_ms;
 	ret->start = song->start;
+	ret->start_ms = song->start_ms;
 	ret->end = song->end;
+	ret->end_ms = song->end_ms;
 	ret->last_modified = song->last_modified;
 	ret->pos = song->pos;
 	ret->id = song->id;
@@ -396,6 +413,14 @@ mpd_song_get_start(const struct mpd_song *song)
 	return song->start;
 }
 
+unsigned
+mpd_song_get_start_ms(const struct mpd_song *song)
+{
+	assert(song != NULL);
+
+	return song->start_ms;
+}
+
 unsigned
 mpd_song_get_end(const struct mpd_song *song)
 {
@@ -404,6 +429,14 @@ mpd_song_get_end(const struct mpd_song *song)
 	return song->end;
 }
 
+unsigned
+mpd_song_get_end_ms(const struct mpd_song *song)
+{
+	assert(song != NULL);
+
+	return song->end_ms;
+}
+
 static void
 mpd_song_set_last_modified(struct mpd_song *song, time_t mtime)
 {
@@ -508,15 +541,19 @@ mpd_song_parse_range(struct mpd_song *song, const char *value)
 	}
 
 	song->start = start > 0.0 ? (unsigned)start : 0;
+	song->start_ms = start > 0.0 ? (unsigned)(start * 1000) : 0;
 
 	if (end > 0.0) {
 		song->end = (unsigned)end;
+		song->end_ms = (unsigned)(end * 1000);
 		if (song->end == 0)
 			/* round up, because the caller must sees that
 			   there's an upper limit */
 			song->end = 1;
-	} else
+	} else {
 		song->end = 0;
+		song->end_ms = 0;
+	}
 }
 
 static void