[action] add generic order action.
(cherry picked from commit 6f8245d74ee9a333955a6d8a81027bde9e4f6673)

Conflicts:

	src/Payum/Paypal/ProCheckout/Nvp/PaymentFactory.php
Merge pull request #273 from formapro-forks/baackport-generic-order-action

[action] backport generic order action from master.
Release 0.12.8
Merge branch '0.12'

Conflicts:
	src/Payum/AuthorizeNet/Aim/PaymentFactory.php
	src/Payum/Be2Bill/OnsitePaymentFactory.php
	src/Payum/Be2Bill/PaymentFactory.php
	src/Payum/Offline/PaymentFactory.php
	src/Payum/Payex/PaymentFactory.php
	src/Payum/Paypal/ExpressCheckout/Nvp/PaymentFactory.php
	src/Payum/Paypal/ProCheckout/Nvp/PaymentFactory.php
	src/Payum/Stripe/PaymentFactory.php