Remove repo/pod/image lists

[dboreham]

The files:

./app/data/container-image-list.txt, ./app/data/repository-list.txt and ./app/data/pod-list.txt

are now architecturally redundant because we no longer want to a) pull/build everything, and b) we have stack definitions to define collections of these things.

To remove these we need to add some new code to extract the relevant lists from stack definitions.

[zramsay]

when this gets done, it should also shuffle private repos to the end of setup-repositories, or gracefully skip the cloning of private repos. The existing bug is that if someone doesn't have access to a private repo, then setup-repositories will fail/end at the first private repo is comes across and any public repos necessary that come later on the list, don't get cloned

[dboreham]

Ok, but nobody should be running setup-repositories without a stack now.