Returns the default
GSettingsBackend. It is possible to override
the default by setting the
GSETTINGS_BACKEND environment variable
to the name of a settings backend.
The user gets a reference to the backend.
Available since: 2.28
which will be a dummy (memory) settings backend if no other settings
backend is available.
|The caller of the function takes ownership of the data, and is responsible for freeing it.|