add debugging around dwollacontroller's update and bump version

Conflicts:
	README.md
Move provider and payment_method to private (not actions)
Use custom debug_aware logging method
Checkout for payment source_type against string, not class constant
bump version
use popup for oauth dialog
bump version; update readme
Merge branch '2-0-stable' into 1-3-stable

Conflicts:
	README.md
	app/controllers/spree/dwolla_webhook_controller.rb