Return empty dict for list_pkgs(purge_desired=True) with macports

This fixes #16828
Merge remote-tracking branch 'upstream/develop' into develop
Added the ability to mount on OS X

- This uses the /etc/auto_master config to setup persistent mounts (always as the user running salt)
- As of right now only the root user can read the mount if it's mounted persistently (I recommend simply running this as another user and not persisting)
- Replaces the defaults setting to noowners on OS X
#16991 Fixed pylint issues
Merge pull request #16991 from opdude/osx-mount

Added ability to mount using mount.mounted on OSX