ambiata/ivory — pull request #427 by charleso (2014-11-05 02:34:18+00:00)
Title: Ensure up-to-date snapshot is taken with the latest dictionary

This started as something else, putting the check in `SquashJob.squashFromSnapshotWith`, but slowly moved up to where it is. I _think_ making the dictionary check in `SnapshotManifest` (or at least `Snapshots`) makes more sense.