Move action logic into a new action helper

* Cleanup the view and move logic to a helper
Add auto link gem

* https://github.com/tenderlove/rails_autolink
Make links clickable in notes

* Only link URLs not emails
* Don’t sanitize the output so as to be consistent with simple_format
options
Merge pull request #286 from alphagov/links-in-notes

Make links clickable in notes