[bitwise.c: CVS HEAD] oggpack_writecopy_helper() incorrectly moves buffer pointer
In the HEAD (1.16) version of bitwise.c, the oggpack_writecopy_helper() function
bumps b->buffer (line 175) where previous versions bumped b->endbyte.
Since the 'buffer' field of an oggpack_buffer is an owned pointer when writing,
and is free()d in oggpack_writeclear(), this seems like a (fairly major) bug.