moved fallback APE/ID3 tag loader to song.c

Some plugins used the APE or ID3 tag loader as a fallback when their
own methods of loading tags did not work.  Move this code out of all
decoder plugins, into song_file_update().

src/decoder_api.h

@@ -29,7 +29,6 @@
 #include "input_stream.h"
 #include "replay_gain.h"
 #include "tag.h"
-#include "tag_id3.h"
 #include "audio_format.h"
 #include "playerData.h"