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/pools/index.html.erb

@@ -3,7 +3,6 @@
     <%= render "search", :path => pools_path %>
 
     <%= table_for @pools, width: "100%" do |t| %>
-      <% t.column nil, {width: "5%"} %>
       <% t.column "Name", {width: "60%"} do |pool| %>
         <span class="pool-category-<%= pool.category %>"><%= link_to pool.pretty_name, pool_path(pool) %></span>
         <% if pool.is_deleted? %>