[ckan-dev] Hide empty search facets boxes

[Sean Hammond]

Currently on the dataset search page in 2.0, if a site has no groups,
there's still a box titled "Groups" at the top of the sidebar that just
contains "There are no filters for this search". If the site isn't using
groups at all (which seems common) this useless box will stay pinned at
the top of the page forever, unless they use an IFacets plugin to hide
it.

This also applies to other facet types eg. tags when there are no tags
on the site, etc.

Should a facet box be hidden if there are no objects of that type on the
site to facet by? Is this a feature we should add in 2.1?