gEDA-dev: libgeda error reporting

[Ales Hvezda]

> While working on gattrib, I noticed that libgeda
> prints errors and uses calls like fprintf(stderr, ...).
>
> So when you try to open up a nonexistant file in
> a program using libgeda (gattrib in this case), you
> get errors both from libgeda and from the program.
> Is this intended?

Originally intended, but should be removed or fixed now.
libgeda calls should return error status and if necessary
write something to the log.

-Ales