Changes for SmashPig/Adyen!

When a payment returns from Adyen it should be in the pending
state because we always will need to do further things to it.

And... we need to add metadata to stomp messages such that
smashpig doesn't freak out when it attempts to deserialize.

Change-Id: Ia733b4fb1cabab2ab34e084e96c212d1675538ae
Allowing the OrderID for Adyen to be Resurrected

Otherwise nothing sets it and we lose it!

Change-Id: Iee81d1a78b7d0883139f1b6abe3e92a2d5703b2a