Move more logic to the helper modules

- Diff view changes
-- Only show pool description changes in diff view
-- Conditionally render diff link when applicable values are changed
-- Conditionally show diff view sections when values are changed
- Show renames on index view
-- There is plenty of space
-- This wasn't shown at all for wikis
-- Having to navigate to an alternate page is unwieldy for pools
- Show "posts" as a status on pools
-- This is so all changes among versions are quantified as a status
- Standardize diff/index titles

app/helpers/wiki_page_versions_helper.rb

@@ -1,9 +1,28 @@
 module WikiPageVersionsHelper
-  def wiki_other_names_diff(new_version, old_version)
+  def wiki_version_show_diff(wiki_page_version)
+    previous = wiki_page_version.previous
+    previous.present? && ((wiki_page_version.body != previous.body) || wiki_page_version.other_names_changed)
+  end
+
+  def wiki_version_show_other_names(new_version, old_version)
+    ((new_version.other_names - old_version.other_names) | (old_version.other_names - new_version.other_names)).length > 0
+  end
+
+  def wiki_version_other_names_diff(new_version, old_version)
     new_names = new_version.other_names
     old_names = old_version.other_names
     latest_names = new_version.wiki_page.other_names
 
     diff_list_html(new_names, old_names, latest_names, ul_class: ["wiki-other-names-diff-list list-inline"], li_class: ["wiki-other-name"])
   end
+
+  def wiki_version_title_diff(wiki_page_version)
+    previous = wiki_page_version.previous
+    if previous.present? && (wiki_page_version.title != previous.title)
+      name_diff = diff_name_html(wiki_page_version.title, previous.title)
+      %((<b>Rename:</b>&ensp;#{name_diff})).html_safe
+    else
+      ""
+    end
+  end
 end