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
[OrderBundle] Item & order cost can't be negative
Merge pull request #912 from stloyd/bugfix/order_total_cost

[OrderBundle] Item & order cost can't be negative
Adjust models constructors & phpdocs
Merge pull request #927 from stloyd/bugfix/adjust_models

Adjust models constructors & phpdocs
Move order states to its interface

add some states, and delete unused confirmation mechanism
Add OnHold shipment state
Add InventoryUnit states
Add Payment states
Moved debug toggle from AppKernel to web/app_dev.php