This makes easier to write a module that can be both dynamic and static.
It will allow to statically build modules from glib-networking, for
example.
A module can rename its g_io_module_load() function to
g_io_<modulename>_load(), and then an application which links statically
against that module can call g_io_<modulename>_load(NULL) to register
types and extension points from the module. If a module is loaded
dynamically, its load() function will continue to be called with a
non-NULL GIOModule instance.
https://bugzilla.gnome.org/show_bug.cgi?id=684282
0e7b82abb9