[ Michael Vogt ]
* DistUpgrade/DistUpgradeCache.py:
  - fix nvidia detection, thanks to Brian Murray
* DistUpgrade/xorg_fix_proprietary.py:
  - fix crash when apt_pkg is not initialized (LP: #942106)
* DistUpgrade/DistUpgradeController.py, DistUpgrade/mirrors.cfg:
  - support upgrades with commercial-ppas in the sources.list
    (LP: #939461) and add tests
* UpdateManager/UpdateManager.py:
  - fix inaccurate string, thanks to JohnNapster (LP: #942590)

[ Brian Murray ]
* DistUpgrade/removal_blacklist.cfg: 
  - Only blacklist unity-2d, not all packages whose names start with
    unity-2d.  (LP: #940196)