- point to main Calamares site in the 'part of' headers instead
of to github (this is the "this file is part of Calamares"
opening line for most files).
- remove boilerplate from all source files, CMake modules and completions,
this is the 3-paragraph summary of the GPL-3.0-or-later, which has
a meaning entirely covered by the SPDX tag.
- *AppImage example config*: this is old AppImage configuration,
basically unmaintained, but copied from the **other** example
config files which are CC0-1.0 as well.
- *Sample Linux distro*: The example Linux distro has a handful
of trivial files, a bogus `/etc/issue`, that kind of thing.
- The bash completions are GPL-3.0-or-later
- FreeBSD packaging information is BSD-2-Clause