[Vorbis] ov_read, callbacks and 0 bytes read

[Andrew Lentvorski]

Ralph Giles wrote:
> Note that the code for Tremor needs to be slightly different because it 
> uses a different ogg implementation, but you should be able to figure it 
> out from Tremor's vorbisfile.c

Actually, even libvorbis doesn't compile decoder_example.c.

The problem is that ogg_sync_init doesn't actually exist anywhere in the 
codebase.  Where did it go?

-a