[m-rev.] for review: start using pragma external_pred

[Julien Fischer]

Hi Zoltan,

On Fri, 21 Aug 2015, Zoltan Somogyi wrote:

> The diff is straightforward and does not need review. The only
> thing worth reviewing is whether it is too early to start using
> :- pragma external_pred, which was introduced almost exactly
> one month ago.

I have no objections, there have been plenty of successful rotd builds
since then and my local versions are all up-to-date.

Cheers,
Julien.