guardian/frontend — pull request #5845 by janua (2014-09-04 12:54:55+00:00)
Title: Collection History

This PR adds `lastUsed` to a collection.

On updates to a collection in live, it pushes the `id` to the head of `lastUsed`.
On updates to draft, it updates `lastUsed` upon publishing only; It will be the difference between `draft` and `live`.

@stephanfowler `previously`? `history`?