Make clear in collaborator UI which version you are on

[timgdavies]

Via @birdsarah:

Recent observation from OC workshop.

Someone has been working on the standard and she went back to a page she's used to go to - which was the Release Candidate. This page now has a warning that she "wasn't on the latest version" so she clicked on the latest version and was taken to it.

But because the page looks identical it wasn't clear that she'd changed versions.

Either we need to display the version somewhere on each page. Or, in the case of someone clicking on that error message, use the messages framework to display a temporary message that they've switched.

I would suggest we do a bit of work on the interface to bring past versions from 1.0.RC onwards clearly into the navigation somewhere, so that the switcher isn't just hidden away at the bottom of the page now that we will have multiple versions people want to engage with.