/wiki_page_versions/diff: use SetDiff to diff other_names.

Use SetDiff instead of DiffBuilder to generate diffs for wiki page other
names. SetDiff is what we use for artist other names.

app/views/application/_diff_list.html.erb

@@ -1,21 +1,21 @@
-<%# diff %>
+<%# diff, ul_class, li_class %>
 
-<ul class="diff-list">
+<%= tag.ul class: [*ul_class] do %>
   <% diff.added.each do |item| %>
-    <%= tag.li item, class: (item.in?(diff.obsolete_added) ? "obsolete added" : "added") %>
+    <%= tag.li item, class: ["added", ("obsolete" if item.in?(diff.obsolete_added)), *li_class] %>
   <% end %>
 
   <% diff.removed.each do |item| %>
-    <%= tag.li item, class: (item.in?(diff.obsolete_removed) ? "obsolete removed" : "removed") %>
+    <%= tag.li item, class: ["removed", ("obsolete" if item.in?(diff.obsolete_removed)), *li_class] %>
   <% end %>
 
   <% diff.changed.each do |old, new| %>
     <%= tag.li class: "changed" do %>
-      <%= tag.span old, class: "removed" %>→ <%= tag.span new, class: "added" %>
+      <%= tag.span old, class: ["removed", *li_class] %>→ <%= tag.span new, class: ["added", *li_class]  %>
     <% end %>
   <% end %>
 
   <% diff.unchanged.each do |item| %>
-    <%= tag.li item, class: "unchanged" %>
+    <%= tag.li item, class: ["unchanged", *li_class] %>
   <% end %>
-</ul>
+<% end %>

app/views/wiki_page_versions/diff.html.erb

@@ -6,9 +6,8 @@
   <% if @thispage.visible? %>
     <p>Showing differences between <%= compact_time @thispage.updated_at %> (<%= link_to_user @thispage.updater %>) and <%= compact_time @otherpage.updated_at %> (<%= link_to_user @otherpage.updater %>)</p>
 
-    <div>
-      <%= wiki_other_names_diff(@thispage, @otherpage) %>
-    </div>
+    <%= wiki_other_names_diff(@thispage, @otherpage) %>
+
     <div>
       <%= wiki_body_diff(@thispage, @otherpage) %>
     </div>