I vaguely remember reading ages ago that a really well cut nut should be able to just sit in position on its own, ie, it won't fall out if you turn the guitar upside down. The idea was not that glue should not be used at all, rather that emphasis should be placed on workmanship in the first place. As the nut is likely to be replaced at some point, it seems to be a compromise between keeping the nut stable whilst playing, changing strings etc, etc, and being able to remove the nut and replace it without taking any wood with it,..........at least on quality instruments. Therefore I would imagine that superglue is a no-no. My memory is that whoever wrote which ever article it was, suggested a small blob of glue in the centre of the bottom of the nut and that would spread when pressure is applied. Apparently just a small amount just to hold in place. Hide-glue would seem to be the obvious choice due to its ability to soften when re-heated thus making removal relatively easy. I doubt though that anyone would cook up hide glue just to 'do a nut'. I not going to tell you which glue to use cos I don't actually know, but I would guess that a standard wood glue would be fine. Maybe your next reply will give you a definitive answer.
When I started fixing up guitars, which I do as a hobby, I was recommended to do exactly as David recommends, and to use Alipfatic resin type glue (e.g. Titebond woodglue). Next time it needs to come off, You just tap it lightly in parallell with the fretboard in the direction towards the headstock.
Speaking of hideglue, I think Titebonds Liquid Hideglue would be a just as good option.
I usually place a small drop (really small) of clear nail polish in the center of the nut, at the 90° junction of where the fretboard meets the neck. Seems to hold it just fine and it's a clean "break" to remove the nut.
Wood glue is the best choice ( Titebond, Elmers ) just few small drops. The pressure of the strings will hold it in place. A tap to the nut will easily remove it. Hide glue would be overkill and super glue a disaster.
I put one little drop of CA glue (superglue) on the facet of the nut that butts up against the fingerboard. This method allows me to safely remove the nut with a light tap and cleans up nicely with a razor blade. If the nut is glued to the neck wood and not the fingerboard, you run the risk of tearing wood (especially mahogany) up with the nut upon removal. I also put a slight bevel on headstock veneer finish at the nut with a 3-corner file with a ground edge to avoid chipping and make it easier to remove in the future.