config.py: Adds squashfs_* config opts
cli.py: Modifies print_shortlist info unpacking
api.py: Modifies supported_types() module checking
Initial update to setup.py for the new structure

TODO: make the modules included configurable from the ebuild.
Fix errors in overlay updates.

Original problem reported in #gentoo-overlays by user quinso.
setup.py: Fix typo
setup.py: Fix another typo
setup.py: Adds new utility scripts to setup
mounter.py: Renames "repo" var to "repos", _check_selection()