Update to Rails 3.1.14 and Unicorn.
Re-adds PDFKit gem.
Revert to jQuery-rails 2.3.0
Fixes javascript for showing email fields.
Removes need for a participant code.
Changes wording on page 1.
Removes reference to followup on exit screens.
Removes question regard feedback copy from report.
More Unicorn configuration.
Remove referral page from report flow.

Referral service is not being offered to random people who do
the new e-SBI.
Updates wording and links for support, facts and tips.
Some more wording and styling changes.

Removes custom link colouring, to go with the standard colours
and reduce potential confusion amongst the participants.
Removes assignment to control condition.
Updates to Rails 3.2.21.

Locks rmagick at 2.13.3 for now as 2.13.4 does not compile.
Adds Heroku gems.