expose relation lifecycle state to 'juju status'

Excerpts from Mark Mims's message of Fri Aug 19 17:14:01 UTC 2011:
> Public bug reported:
>
> I'd like to know when hooks complete execution.
>
> ** Affects: ensemble
> Importance: Undecided
> Status: New
>

So, as explained in bug:828411 this isn't about relation lifecycle status. hooks
can be executing at any time when the relation status lifecyle is up. In fact that's
what it means. If its down, hooks aren't executing.

afaics this bug is really a request to have ensemble status reporting the
currently executing hook on a unit, or to have a history of the hooks executed
on a unit.

seems like a valid request to allow hooks to say "the relationship is working" or "the relationship is not working" in a way other than open-port or errors during a hook. I'd like to see a real use case though. Leaving as New, but setting, importance to Wishlist.