These job plugins work similarly to view modules, with the following
differences:
* These jobs need to link only libcalamares, not libcalamaresui. For
this reason, PluginFactory was moved from libcalamaresui to
libcalamares. (It depends only on QtCore.)
* Instead of deriving from ViewModule, derive from CppJob (which is a
subclass of Job).
* Like process and Python jobs, a job plugin is a single job, whereas a
ViewModule can generate a whole list of jobs.
The CppJob and CppJobModule classes are new. In Module::fromDescriptor,
the combination type=job, intf=qtplugin is now supported and mapped to
CppJobModule.
In order to avoid deep copies, Qt containers over which we iterate must be const
The remaining unported cases require qAsConst (Qt 5.7) or std::as_const (C++17)
This allows us to make GlobalStorage a QObject, with disabled copy
constructor. And thanks to this change, GlobalStorage now emits
changed() every time an insert or remove is performed.
Convert Python bool type from/to C++/QVariant bool (QVariant::Bool) in
PythonHelper::variantToPyObject and PythonHelper::variantFromPyObject.
This fixes the "override" option and any booleans in the "defaults" list
in grubcfg.conf.
Point the lib/calamares/libcalamares.so symlink for the Python modules
directly to the versioned lib/libcalamares.so.VERSION library rather
than to the lib/libcalamares.so symlink. This allows distributions to
install the lib/libcalamares.so symlink to a development package and
only ship lib/libcalamares.so.VERSION and lib/calamares/libcalamares.so
in the runtime package. It is also marginally faster (because only one
level of symlinks has to be resolved instead of two).
(I know this works because I have been manually fixing up this symlink
in the Fedora specfile so far.)
