Add test_complexTradeModel to make sure that trade model line is capable of...

Add test_complexTradeModel to make sure that trade model line is capable of handling complex trading rules we see in real business. More use cases to be added later.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@30952 20353a03-c40f-0410-a6d1-a30d3c3de9de