Divert outcome for countries with no embassies.

In the case where the registree is now in another country and this country does not have an embassy the correct outcome should be shown.
Fix intro for FCO outcome
Make registration country mappings common to all
Use registration country mappings
Merge branch 'master' of github.com:alphagov/smart-answers
Merge branch 'master' into register-a-birth
Merge pull request #190 from alphagov/register-a-birth

Register a birth overseas - amends
Merge commit '1ab6c94b70c33aabdc53374ea577433fac0c7ff9' into HEAD