Get confirmation URL working

[aneilbaboo]

Currently, the confirmation email contains a url to the API confirmation endpoint. This ends up with the user seeing a blank screen after clicking confirm, instead of a confirmation screen.

Two possible strategies:

1. customize the email template (we have to anyway), and generate url ourselves from template params
2. add a redirect from the API-based endpoint, as provided by the confirmable docs. Kind of gross, but on the plus side, this should only affect browsers anyway.