Add relation between order and cart

	modified:   core/lib/Thelia/Model/Base/Cart.php
	modified:   core/lib/Thelia/Model/Base/CartQuery.php
	modified:   core/lib/Thelia/Model/Base/Currency.php
	modified:   core/lib/Thelia/Model/Base/Customer.php
	modified:   core/lib/Thelia/Model/Base/Lang.php
	modified:   core/lib/Thelia/Model/Base/Module.php
	modified:   core/lib/Thelia/Model/Base/Order.php
	modified:   core/lib/Thelia/Model/Base/OrderAddress.php
	modified:   core/lib/Thelia/Model/Base/OrderQuery.php
	modified:   core/lib/Thelia/Model/Base/OrderStatus.php
	modified:   core/lib/Thelia/Model/Base/OrderVersion.php
	modified:   core/lib/Thelia/Model/Base/OrderVersionQuery.php
	modified:   core/lib/Thelia/Model/Map/CartTableMap.php
	modified:   core/lib/Thelia/Model/Map/OrderTableMap.php
	modified:   core/lib/Thelia/Model/Map/OrderVersionTableMap.php
	modified:   local/config/schema.xml
	modified:   setup/thelia.sql
	new file:   setup/update/2.0.4.sql