Musepack SV7 decoding support

Originally committed as revision 7375 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/allcodecs.c

@@ -197,6 +197,7 @@ void avcodec_register_all(void)
     REGISTER_ENCODER(MP3LAME, mp3lame);
 #endif
     REGISTER_DECODER(MP3ON4, mp3on4);
+    REGISTER_DECODER(MPC7, mpc7);
 #ifdef CONFIG_LIBVORBIS
     if (!ENABLE_VORBIS_ENCODER)  REGISTER_ENCODER(OGGVORBIS, oggvorbis);
     if (!ENABLE_VORBIS_DECODER)  REGISTER_DECODER(OGGVORBIS, oggvorbis);