table builder: fix various incorrect css classes.

Change calling convention to explicitly indicate whether the attributes
are for the <th> element or the <td> element. Fixes various cases where
the two were mixed up.

* Fix .col-expand classes not being set correctly on the /post_versions,
  /pool_versions, and /notes pages.

* Fix .updater and .updated-at classes not being set correctly on the
  /forum_topics page.

* Fix the name param being ignored (noticeable in the post count field
  on the /tags page).

* Don't pass empty string when column has no name.

app/views/news_updates/index.html.erb

@@ -7,7 +7,7 @@
         <%= link_to_user news_update.creator %>
       <% end %>
       <% t.column :message %>
-      <% t.column "" do |news_update| %>
+      <% t.column do |news_update| %>
         <%= link_to "Edit", edit_news_update_path(news_update) %>
         | <%= link_to "Delete", news_update_path(news_update), :method => :delete %>
       <% end %>