Starter for a new version of the pledge API, which will be tested and
more RESTful.
Expose and use the new Pledge handler.

Adds tests, and production versions of the factored-out
dependencies. Changes pledge.jade to use the new handler.
Merge branch 'master' into new-handler

Conflicts:
	markup/pledge.jade
Change the generic "PaymentProcessor" to "StripeBackend".
Bugfix: I wasn't updating first and last name in the model
Merge branch 'master' into new-handler

Conflicts:
	backend/main.py
Merge pull request #60 from MayOneUS/new-handler

New, tested version of the pledge handler