Code review comment for lp:~jibel/ubuntu-cdimage/support_ubuntu_subproject

Thanks for the merge request! I just took a quick look at it for now and I need to still think about all the consequences of the change. For now one thing that needs fixing: tests. There's one test failing right now, might need some tweaking.

To run the tests, just execute ./run-tests .

Let me get back to you with a final review tomorrow