Disallow books with dim<1 in floor0.
svn path=/trunk/vorbis/; revision=17558
info->books[j]=oggpack_read(opb,8);
if(info->books[j]<0 || info->books[j]>=ci->books)goto err_out;
if(ci->book_param[info->books[j]]->maptype==0)goto err_out;
info->books[j]=oggpack_read(opb,8);
if(info->books[j]<0 || info->books[j]>=ci->books)goto err_out;
if(ci->book_param[info->books[j]]->maptype==0)goto err_out;
+ if(ci->book_param[info->books[j]]->dim<1)goto err_out;