- 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.
The build instructions are not that interesting, it's a toss-up
between CC0 and BSD-2, but because other CMake bits are BSD-2-Clause,
apply that to more CMakeLists. The copyright date isn't all that
accurate, but these are just inconsequential files.
While here, tidy up and get rid of some useless intermediates.
Module descriptors are now module.desc, no configuration allowed inside.
Module config files are <modulename>.conf, installed in
share/calamares/modules.
settings.conf is read from /etc/calamares, then share/calamares, and if
running with --debug also in the current dir.
Module config files are read from /etc/calamares/modules, then
share/calamares/modules, and if running with --debug also in
src/modules/<modulename> relative to the current dir.
