CHANGELOG.md in sk_api_schema-0.8.8 vs CHANGELOG.md in sk_api_schema-0.9.0

@@ -1,9 +1,19 @@
 # SalesKing API Changelog
 
 See [commit messages](https://github.com/salesking/sk_api_schema/commits/) for details.
 Also sign up to our [Developer Newsletter](http://www.salesking.eu/dev/newsletter/) to stay up-to-date !!!
 
+##2013-12
+
+* add cost_total, gross_margin to documents
+* rename product.cost_price to cost
+
+line_item:
+* remove use_product switch. Now copy product fields into item whenever a product_id is set.
+* remove required quantity and position, now defaulting to 1
+* add cost, cost_total, gross_margin
+
 ##2013-10
 
 * add net_total, gross_total to line item
 * add category_name, cost_price fields to product