Remove the parent_id from the global event. Remove the parent
and owner from the global object.
Use properties instead to mark parents and owners of objects.
Properties are easier to control for client exported objects and
usually a simple parent/child is not enough. For example, a client
exported node has the client as a parent but also the factory that
created the node.
Pass a factory_name in the object_info of monitor and device.
Restructure the factory name to mean something functionaly. With
the factory to library mapping this then means that the implementation
of certain factories can be configured in the config file.
