Introduced invoices and deliveries. Integration (especially of deliveries) isn't finished yet.

app/models/article_category.rb

@@ -1,3 +1,13 @@
+# == Schema Information
+# Schema version: 20090102171850
+#
+# Table name: article_categories
+#
+#  id          :integer(4)      not null, primary key
+#  name        :string(255)     default(""), not null
+#  description :string(255)
+#
+
 class ArticleCategory < ActiveRecord::Base
   has_many :articles