[payum][paypal] add suppor of instant notifactions.
fix comments.
fix notify order action class.
fix sync request not supported.
Add easy way to disable inventory tracking.

Currently inventory is always being tracked (resulting in backorders if not replenished).
This PR adds a simple NoopInventoryOperator and a configuration switch.
Use right form types and default data
Merge pull request #863 from Sylius/add-product-action-tweaks

Use right form types and default data for the "add production promotion action"
[paypal] add specs for notify action.
Add NotBlank requirement to credit card number

Funny how we missed this, but except for the cardholder name, none of the credit card fields were required..
Found this out the hard way in production :)

Also, I'm adding a leading zero to expiry month, in keeping with other checkout forms out there.
fix spec fails on php 5.3
Merge pull request #725 from formapro-forks/paypal-notifications

[payum][paypal] add suppor of instant notifactions.
Merge pull request #866 from Richtermeister/fix-credit-card-validation

Add NotBlank requirement to credit card number
Move from private to protected

in behat contexts
Merge pull request #799 from winzou/protected-context

[Behat] Move from private to protected
Be2bill onsite implementation
Add SecureNotifyAction
Rename NotifyAction
Update payment details
Update to PayumBundle 0.7.3
Add NotifyAction to payum config