artist versions: rearrange layout to better fit small screens.

* Move group name beneath the artist name.
* Replace 'Active' column with '(deleted)' notice next to artist name.
* Combine updater, updated at, and ip address fields in single column.
* Combine templates for standard listing and revert listing (only
  difference is presense of 'Revert to' column).

app/views/artist_versions/index.html.erb

@@ -2,12 +2,7 @@
   <div id="a-index">
     <h1>Artist History</h1>
 
-    <% if params.dig(:search, :artist_id).present? %>
-      <%= render "revert_listing" %>
-    <% else %>
-      <%= render "standard_listing" %>
-    <% end %>
-
+    <%= render "standard_listing" %>
     <%= numbered_paginator(@artist_versions, :search_count => params[:search]) %>
   </div>
 </div>