Worldwide office access and opening times

Tracker: https://www.pivotaltracker.com/story/show/44882697

This story replaces the existing method for defining access and opening time information for worldwide organisations (via a corporate info page type) with a new separate model. This was done to give FCO greater flexibility when setting this access information. They can now define default access information that applies across all offices at an organisation, as well being able to give individual offices their own custom access information as required.

This story has taken loads longer than I could ever have imagined. The main issue was that because of the non-standard resourceful routing on worldwide offices, I went round in circles a bit trying to get the new polymorphic controller for AccessAndOpeningTimes to work. I've tidied up the commits as best I could with an epic rebase, so hopefully it all makes sense now.

I'm not entirely happy with the current admin UI for administering this information, but it works and Ross is happy with it as a first iteration. There will be additional stories to translate this access information, and it makes sense to tidy things up then. I'd suggest giving worldwide offices their own show page, with the controls for managing the overrides and their translations available there.