Force the locale to en for travel-advice

These pages haven't been localised at the moment.
Refactor TA country page to use summary field

No longer need to create a dummy part etc.  We also no longer have 2 URLs for the first part.
Fix print view for a country with no parts.
Hide parts navigation for countries with no parts.
Revert "Move common publication_metadata view into /shared directory"

This reverts commit 45e221cc023cb8ca20caf096a1ffc8d96a3ff526.
Update country metadata(updated etc) to match designs.
Fix alignment of printer-friendly page link
Merge pull request #214 from alphagov/travel-advice-country

Update travel-advice country page with new deisgns.