Add tokens to payments

Will be used by dibs_callback_url

    /dibs/callback/:id/:token
Add DibsController for dibs return pages

http://tech.dibspayment.com/node105revisions6669revert/dpwhostedoutputparametersreturnpages
Use Website#webshop_live?

Abstract away webshop_live == "1"
Merge pull request #14 from standout/dibs-callback-url

Dibs callback url