Add security step event
Add OrderUserListener to cart initialize event
Add EventListener to complete Order
Add post creation Order events
Set OrderShippingState to checkout by default
Always flush between pre and post payment
Add paymentState setter
Listen to payment.pre_state_change event

and dispatch order.pre_pay from where shipments are being prepared
Fix feedbacks
Use ObjectManager instead of EntityManager
Use Interface instead of concrete EventDispatcher
Merge pull request #899 from winzou/event/checkout

The Events - Checkout Revolution
[CoreBundle] Fixed typo in OrderPaymentListener
Fix issues found by SensioLabsInsight & Scrutinizer-CI