A potentially emergency module is one that has EMERGENCY
(in CMake) or emergency: true (in module.desc) set.
Any such module must also set emergency: true in the
configuration of the module. This is to allow for
instances of a module that **don't** run as emergency
modules, alongside actual emergency ones.
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.
