claim action should set a session

It should set it to itself so that if the user goes to the technical
help page, it should return the user to the confirmation page.

Redirect the user when requesting tech help

But don't redirect them back to the tech help form or the feedback form.
renamed variable
unit tests for redirect from technical help form submission
implemented redirect in
feedback controller
refactoring: created return_to() method
added referrer_is_feedback_form?()
removed unneeded code
Merge pull request #404 from ministryofjustice/redirect_to-ad-form

Redirect to ad form