guardian/frontend — pull request #2470 by janua (2013-12-04 19:08:13+00:00)
Title: Uk Alpha

This adds:

- A path for dropping the opting in and opting out of UK Alpha via the cookie `GU_UK_ALPHA`.
- A switch `UkAlphaSwitch` for switching the UK Alpha on and off.

I have also added a path lookup for the `renderFront` method in `FaciaController`. This will serve `uk-alpha` under three conditions:
- The path is `uk`
- The UkAlphaSwitch switch is on
- We think the requests `Edition` is `Uk`
- They have the correct header `X-Gu-Uk-Alpha=true`