Another Packaging/Review Guidlines clarification

[Christoph Wickert <cw-spam arcor de>]

How about adding something like:

> Must - A package should always use the latest stable upstream release.
> If for any reason this isn't possible, this has to be explained in the
> review / review request.

to the Packaging/Review Guidelines? Not sure if this should be a MUST or
a SHOULD.

Chris