Update the DVLA address on SORN start page

As requested by DVLA: https://www.pivotaltracker.com/story/show/73709066
Merge pull request #625 from alphagov/update-dvla-sorn-address

Update the DVLA address on SORN start page
Guide print stylesheet: from gov.uk text duplicated
Merge pull request #626 from alphagov/print-guide-from-govuk-dup

Guide print stylesheet: from gov.uk text duplicated

This fixes this issue:
https://govuk.zendesk.com/agent/#/tickets/764799
When printing out a guide, the title is followed by "a guide from GOV.UK from GOV.UK"
This change fixes that duplication. 
I will be opening a new pivotal ticket to track the issue that "from GOV.UK" is being added to the print copy even for Welsh print-outs: this is a less straightforward change as it ties in to another discussion on locales on HTML pages.
Filter headings last on travel advice index

In the travel advice index script (which filters countries) was filtering
the alphabet headings before filtering the actual countries when no filter
query is given. Thus, if the user entered a search term and then deleted it,
the filter did not correctly re-show all the headings.
Make the beta SORN service more prominent

The beta service should now be displayed above the
original service.
Update SORN integration tests

Make the SORN tests match the tweaked page layout
Configure asset host in development mode.

When run under `govuk_setenv`, this configures the asset host to point
at the assets-origin on the dev VM.  This will give us better dev-prod
parity, and enable running this behind the router in dev.
Merge pull request #630 from alphagov/asset_host_in_dev

Configure asset host in development mode.
Merge pull request #628 from alphagov/fix-travel-advice-filter

Filter headings last on travel advice index
Increase weight of Tax Disc Beta AB to 100%

This shows the beta option as the most prominent option to the majority
of users.
Merge pull request #629 from alphagov/make-sorn-beta-primary-option

Make the beta SORN service more prominent
Remove links on organisations in search results

These links often went to a target which didn't have the relevant
anchor, they don't get much usage, and we want to make things simpler
here so we can iterate the organisation pages more easily.

https://www.pivotaltracker.com/story/show/66652478
Merge pull request #632 from alphagov/remove-search-jump-links-from-organisations

Remove links on organisations in search results
Change frontpage content for minister reshuffle
Merge pull request #633 from alphagov/home-page-reshuffle

Change frontpage content for minister reshuffle
Revert "Merge pull request #629 from alphagov/make-sorn-beta-primary-option"

This reverts commit be05d8d79fbde1be0263f20204c77d774d45e6ff, reversing
changes made to e88c9e48daab5675b5b935e9db3530b74aa7694b.

DVLA have requested that this isn't deployed to production yet
Merge pull request #634 from alphagov/revert-sorn-page-update

Revert SORN page update from #629
Add dot at end of minister reshuffle text for consistency
Merge pull request #635 from alphagov/minister-reshuffle-dot-consistency

Add dot at end of minister reshuffle text for consistency