[m-rev.] for review: Do not use stateful-error style in io.m; minor bug fixes.

[Peter Wang]

On Wed, 28 Sep 2016 10:19:03 +1000 (AEST), Julien Fischer <jfischer at opturion.com> wrote:
> 
> Hi Peter,
> 
> On Tue, 27 Sep 2016, Peter Wang wrote:
> 
> > library/io.m:
> >    Make remaining I/O primitives return error codes directly to Mercury
> >    wrapper predicates, instead of saving the error in a global variable
> >    to be looked up separately.
> >
> >    Delete stateful-error predicates and global variables.
> >
> >    Delete unnecessary foreign exported procedures.
> 
> ...
> 
> That's fine.

Thanks for the reviews.

Peter