Redirect back to PP after 10486

Conflicts:
	app/controllers/paypal_transactions_controller.rb
	app/models/paypal_token.rb
	db/schema.rb
Redirect user back to PayPal if 486 error
TransactionService.preauthorize
PP Error with cid and txid
Move paypal controllers under PaypalService namespace
Update transactions_api.md

Add listing_id
Merge pull request #725 from sharetribe/redirect-486

Redirect 486