- Let's just have one header definining export- and visibility-
macros for Calamares. They are still selected based on the
export flags (*_PRO), just defined in one header instead of two.
- These methods are used for multi-page view-steps, which are rare.
For all the others, just drop the empty implementation and defer
to the base class.
Fixes CAL-345.
Changing group of home dir to the default "users" group might be a security risk
because every user which belongs to the default "users" group
might be able to access private data on home dirs of other users.
