[Merge] lp:~brian-murray/ubuntu-release-upgrader/bug-1302380 into lp:ubuntu-release-upgrader

[Michael Vogt]

Thanks again for this branch, I looked at this in more detail this morning and would like to use a slightly extended version of this work from here: 
https://code.launchpad.net/~mvo/ubuntu-release-upgrader/partial-upgrade-cleanup/+merge/214685

-- 
https://code.launchpad.net/~brian-murray/ubuntu-release-upgrader/bug-1302380/+merge/214349
Your team Ubuntu Core Development Team is requested to review the proposed merge of lp:~brian-murray/ubuntu-release-upgrader/bug-1302380 into lp:ubuntu-release-upgrader.