[@core] working definition for the minimal package set

[Bill Nottingham]

Matthew Miller (mattdm at fedoraproject.org) said: 
> > Well, it would be weird that the "minimal" installation is actually not
> > "minimal" at all, but the "container" installation is.
> 
> That would be weird. But fortunately, it's @core, not @minimal. So we could
> easily have @minimal, @core, and @standard, each with different targets.

@core is what's shown as the minimal install in anacona. We could do some
renaming, but having @minimal, and having it *not* be the minimal install
in anaconda, sounds like a really bad idea.

Bill