Add a BETA icon to the derived distroseries pages

[Gavin Panella]

Also to the derivation portlet on DistroSeries:+index.

[Martin Pool (mbp)]

I wonder, just thinking out loud, if rather than adding and removing
these one by one, Launchpad could have some kind of generic mechanism
that says

 on pageid x
 in dom element y
 insert a beta/new/whatever badge

[Gavin Panella (allenap)]

I think that's an interesting idea, but it's probably overkill unless
we're expecting to do it a lot. Perhaps if the presentation could be
enshrined in a CSS class that would be enough; asking around to find
out the "right" way to do this is taking a lot more time than editing
the templates.

[Launchpad QA Bot (lpqabot)]

Fixed in stable r13854 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/13854>.