[rfc] Fix committed/released distinction

[Martin Pool]

Vincent, you have some very interesting points there.  lp:kanban ought
to be able to understand that bugs can be targeted to milestones and
the milestone can be either released or not, and it could draw them
differently based off that.  Replicating that information across all
the bugs is inefficient (and for that matter also generates bugspam.)
<http://pad.lv/754375>

In fact, there's a fairly old lp bug saying they ought to just be
merged <http://pad.lv/163694>.

OK, so, fair enough: let's not make this change; I'll try to fix
754375 in the kanban software instead.

Martin