Second part of stock-integration.

Introduced StockArticle and a special page for ordering from stock. StockChanges will be created and the StockArticle.quantity
updated in 'order.close!'.

app/models/article.rb

@@ -22,6 +22,7 @@
 #  updated_at          :datetime
 #  quantity            :decimal(, )     default(0.0)
 #  deleted_at          :datetime
+#  type                :string(255)
 #
 
 class Article < ActiveRecord::Base
@@ -32,9 +33,7 @@ class Article < ActiveRecord::Base
   belongs_to :supplier
   belongs_to :article_category
   has_many :article_prices, :order => "created_at"
-  has_many :stock_changes
 
-  named_scope :in_stock, :conditions => "quantity > 0", :order => 'suppliers.name', :include => :supplier
   named_scope :available, :conditions => {:availability => true}
 
   # Validations
@@ -173,11 +172,6 @@ class Article < ActiveRecord::Base
     end
   end
 
-  # Update the quantity of items in stock
-  def update_quantity!
-    update_attribute :quantity, stock_changes.collect(&:quantity).sum
-  end
-
   protected
   
   # Checks if the article is in use before it will deleted