added popular exploration, added order:rank

app/presenters/post_set_presenters/base.rb

@@ -0,0 +1,21 @@
+module PostSetPresenters
+  class Base
+    def posts
+      raise NotImplementedError
+    end
+    
+    def post_previews_html(template)
+      html = ""
+
+      if posts.empty?
+        return template.render(:partial => "post_sets/blank")
+      end
+
+      posts.each do |post|
+        html << PostPresenter.preview(post)
+      end
+
+      html.html_safe
+    end
+  end
+end