anchor.diff:  <%# like Blacklight _facet_limit.html.erb , displays an individual
  -    sidebar facet list. 
  +    sidebar facet list.
   
       locals required:
         * solr_field: name of facet field configured in BL configuration (passed in by standard BL)
         * One of EITHER:
           * display_facet: (passed in by standard BL)
           * paginator: Blacklight::FacetPaginator, passed in by our BlacklightFacetBrowse
  -          action, when retrieving AJAX results for sidebar. 
  +          action, when retrieving AJAX results for sidebar.
   
       But we add a search
       box, with ajax instant search -- we're actually
  -    going to call out to the existing facet_limit, woot! 
  +    going to call out to the existing facet_limit, woot!
   
       If you want searchable box in sidebar facet, you configure
       use of this partial in your facet configuration (such as in catalogcontroller),
       eg
   
  -        config.add_facet_field  "subject_topic_facet", :label => "Topic", 
  +        config.add_facet_field  "subject_topic_facet", :label => "Topic",
             :limit => true, :browse_field => "subject_topic_browse_facet",
             :partial => "browsable_facet_limit"
   
  
positive.code: 
  <%-
  unless local_assigns[:paginator]
    paginator =    
      Blacklight::Solr::FacetPaginator.new(display_facet.items,        
        :limit => facet_limit_for(solr_field))
  end
  -%>
  
negative.code:     <ul>
        <% paginator.items.each do |item| -%>
          <li>
          <% if facet_in_params?( solr_field, item.value ) %>
            <%# selected facet %>
            <%= content_tag(:span, :class => "selected label") do %>
                <%= BlacklightFacetBrowse::NormalForm.extract_original(item.value) %>
                <%= render_facet_count(item.hits) %>
            <% end %>
            <%= link_to(t('blacklight.search.facets.selected.remove'), remove_facet_params(solr_field, item.value, params), :class=>"remove") %>
          <% else %>
            <%# not yet selected facet %>
            <%= link_to(BlacklightFacetBrowse::NormalForm.extract_original(item.value), add_facet_params_and_redirect(solr_field, BlacklightFacetBrowse::NormalForm.extract_original(item.value)), :class=>"facet_select label") %>
            <%= render_facet_count(item.hits) %>
          <% end -%>
          </li>
        <% end %>
  