ubuntu udd update

[Martin Pool]

I hope those of you at UDS are having fun.  I'm not there, but gz,
vila and jam from the bzr team are.

New in udd in recent weeks:

 * bzr is being updated in the Launchpad buildds, to let large recipe
builds complete
 * udd importer restarted for precise
 * there's a bunch of new variables for deb-version in bzr-builder
that can be used in recipes, including {debupstream-base},
{debversion}, {debupstream}
 * bzr-builder can now build native packages

The biggest change in recent weeks is that we have a new version of
bzr and associated plugins, which should alleviate some out-of-memory
failures when building medium-large trees.  This is
<http://pad.lv/693524>.  We hit some problems with the roll out to
production but it should be finally out later this week.  This will
also make the bzr-builder changes live.

Martin