Add PurchaseStep events

And make OrderStateResolver listen to it
Enable payment validation in backend
Cleanup bundle & component dependencies
Merge pull request #1379 from winzou/manual/payment

Enable payment validation in backend
Merge pull request #1375 from winzou/fix/order-resolver

Add PurchaseStep events
Merge pull request #1399 from stloyd/bugfix/component_deps

Cleanup bundle & component dependencies