* Reimplement iso_extract using 7zip (not requiring root)
So one of the drawbacks of the original implementation is that it required root for mounting/unmount the ISO image.
This is now no longer needed as we use 7zip for extracting files from the ISO.
* Fall back to using mount/umount if 7zip not found
As discussed with others.
Also improved integration tests.
A preliminary set of test targets for "core" supported module that had no independent tests. These will also help us ensure python3 compatibility for those modules and prevent future regressions.
