Remove redundant (post-rails 4) backports

Conflicts:
	config/initializers/active_record_extensions.rb
Connect to the database via localhost in dev and test

Doing this for postgres means that we don't need to add any pg_hba.conf
rules in dev for the app to be able to authenticate as the transition
role, because one of the default rules already allows it. Using host
authentication for postgres will also make dev more similar to production.

This works for mysql in dev too, so we might as well do this on master
to minimise the diff for postgres branches.

This file is overwritten on deployment so this change makes no difference
for production.
Remove PaperTrail patch

* covered pre-rails4 deprecation warning
Make tests quieter

* Transition::Import was quite noisy, printing as it did to $stderr a lot
* Add a global #active= to allow printing of messages to null console
* Remove unused option to print anywhere else but $stderr
* Add #console_puts and #console_prints to route these messages through
* extend class-method using import classes to use these. Don't use
  any raw puts/print
Merge pull request #366 from alphagov/quieter-tests

Make tests quieter
Merge pull request #365 from alphagov/remove-redundancies-post-rails4

Remove redundancies post-Rails 4
Merge pull request #368 from alphagov/connect_to_db_via_localhost

Connect to the database via localhost in dev and test
Add missing leading slash when canonicalising

This means that for a path-like input such as:
  first-level/second-level

we no longer trash it to make:
  /second-level

we instead make it into:
  /first-level/second-level

On the other hand it does mean that other things accidentally pasted into a
paths field will be turned into paths...