Refactored article_categories.

Gemfile.lock

@@ -36,8 +36,12 @@ GEM
     exception_notification (2.4.0)
     fastercsv (1.5.4)
     haml (3.1.1)
+    has_scope (0.5.0)
     hirb (0.3.4)
     i18n (0.5.0)
+    inherited_resources (1.2.2)
+      has_scope (~> 0.5.0)
+      responders (~> 0.6.0)
     jquery-rails (1.0.1)
       railties (~> 3.0)
       thor (~> 0.14)
@@ -84,6 +88,7 @@ GEM
       rake (>= 0.8.7)
       thor (~> 0.14.4)
     rake (0.8.7)
+    responders (0.6.4)
     simple_form (1.3.1)
     thor (0.14.6)
     treetop (1.4.9)
@@ -100,6 +105,7 @@ DEPENDENCIES
   fastercsv
   haml
   hirb
+  inherited_resources
   jquery-rails
   meta_where
   mysql