Add on-hold inventory quantity for the Variant
Hold inventory
Release inventory
Reported fixes
Release inventory, take care about inventory quantity
Fixed specs
Return to payment step if payment failed.
Add translation message.
Add event.
Implemented PurchaseListener
Merge pull request #817 from kayue/feature/failure-payment-flow

Return to payment step if payment failed.
PurchaseListener C fix
Merge pull request #938 from umpirsky/feature/on-hold-inventory

Add on-hold inventory quantity
On hold inventory status fixes
Merge pull request #952 from umpirsky/fix/on-hold-inventory

Fix/on hold inventory
Change properties' visibility to protected.
Merge pull request #962 from kayue/patch-4

Change PurchaseListener properties' visibility to protected.
Configurable purchace redirect route
Fix NoopInventoryOperator after Interface was updated. Also adding spec to prevent this from repeating.
Merge pull request #967 from Richtermeister/fix-noop-inventory

Fix NoopInventoryOperator after Interface was updated. Also adding spec ...