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/dmails/index.html.erb

@@ -31,7 +31,7 @@
           <%= link_to dmail.title, dmail_path(dmail) %>
         <% end %>
       <% end %>
-      <% t.column "" do |dmail| %>
+      <% t.column do |dmail| %>
         <%= link_to "delete", dmail_path(dmail), :method => :delete, :data => {:confirm => "Are you sure you want to delete this Dmail?"} %>
       <% end %>
     <% end %>