enable curator assignment from web ui to admins

[alee]

Either a dedicated admin section of the site or have an admin toggle on the search page that adds extra form functionality to the search (curator select2 | autocomplete box) and button to assign curators to the selected publications

[alee]

Two things need to be fixed with e08d2f440aea68349f77b28fae0ed6c4dc9aba24

1. We need to be able to assign N publications with status=? to a single curator. Probably the fastest way to do this would be to add a status filter to the Publication admin list.
2. PublicationCuractorForm -> PublicationCuratorForm, queryset should be User.objects.filter(is_active=True) instead of User.objects.all()

[alee]

Mostly fixed in #89 - still need to change the PublicationCuratorForm's User queryset to filter out inactive Users @dhruvilpatel