[payum] payum does not store details after user is returned from payment.
[payum][action] remove debug.
Merge pull request #1607 from formapro-forks/payum-do-not-store-details-after-returning-back

[payum] payum does not store details after user is returned from payment
Add ROLE_PREVIOUS_ADMIN to allow switch back
Merge pull request #1609 from amenophis/switch-user-bugfix

Add ROLE_PREVIOUS_ADMIN to allow switch back
[payment] allow set traversable as payment's details.
update UPGRADE file