Correct asset names
Revert "Correct asset names"

This reverts commit 52ecd9fa9dd0d72b06ab0ba7e597a9092b95ff1c.
Pass cancel token back to checkout

Reasoning: as it is we lose the information that an order has been canceled. Better to keep it around so programmers can customise post Paypal failure cancellation experience.

Fixes #63

Conflicts:
	app/controllers/spree/paypal_controller.rb
allow to intercept line items and request details

allows to change the paypal request by overriding the methods in a controller decorator. e.g. to allow digital items.

Fixes #86
Show relevant info on backend payments section

this will only work if the spree branch you are using contains e834f0d5d79a16fd14f38da2cbdb77396d8228da