All backend files are now loaded in the manager, and modules
receive a pointer to a table with data that contains information
about D-Bus objects and handlers. One file describes one interface
for one module.

g_dbus_connection_register_object replaced by
g_dbus_connection_register_subtree.

The interaction between the manager and modules has changed: the
module now returns not xml, but an instance of GDBusInterfaceInfo
(it writes a pointer to this instance to the table with data
received from the manager, a pointer to the vtable is also written
there).