Second pass at adding key files

site/forum/include_sidebar.html

@@ -0,0 +1,20 @@
+<%~if page_id eq 'category_list'%>
+<div class="searchbox blank">
+  <%registered_users || 0%> registered users
+</div>
+<%~elsif search_widget or $forum_id%>
+<%include include_sidebar_search.html%>
+<%~endif%>
+
+<%~if page_id ne 'category_list' and $poll_widget%>
+<%~set adsize = '300x250'%>
+<%include include_ad.html%>
+
+<%~if poll_widget or $forum_id%>
+<%include include_poll_widget.html%>
+<%~endif%>
+<%~endif%>
+
+<%~set adsize = '300x600'%>
+<%include include_ad.html%>
+