Libxo bugs and fixes.

[Simon J. Gerraty]

Phil Shafer <phil at juniper.net> wrote:
> My take is that the missing piece was the ability of xo_flush to
> flush the underlaying (opaque) stream.  The way it's currently coded
..
> uses fflush for stdout, but doesn't call __flbf.  The app needs to
> decide when a flush is needed and calls xo_flush.
..
> Setting the XOF_FLUSH flag should (but doesn't yet) trigger this
> for each xo_* call.  Currently XOF_FLUSH just flushes to the
> writer, but doesn't call the flush function.  I'll add this.

Calling flush for every xo_* call would seem like a bad idea no?
The app/caller is the only one to know when a suitable flush point has
been reached (if necessary).  

It should suffice if xo_flush() does what the name implies.

If someone is using something other than stdio for a handle, they just
need to tell libxo a function to call in response to xo_flush ?

Does it need to be more complicated than that?