(svn r5464) [Behaviour Fix] : When starting the game, the system will now verify the presence of music files in gm forlder.

A song can now be removed from the programmed list (in custom list 1 and 2) by clicking on it.
Added music.c[ch] files, to make it all a bit cleaner.
Now, the name of the gm file is associated with the title of the song.

music.h

@@ -0,0 +1,16 @@
+/* $Id */
+
+#ifndef MUSIC_H
+#define MUSIC_H
+
+#define NUM_SONGS_PLAYLIST 33
+#define NUM_SONGS_AVAILABLE 22
+
+typedef struct SongSpecs {
+	char filename[256];
+	char song_name[64];
+} SongSpecs;
+
+extern const SongSpecs origin_songs_specs[NUM_SONGS_AVAILABLE];
+
+#endif //MUSIC_H