Enh: bind get_instance & properties in package __init__
Enh: bind get_instance & properties in package __init__

So that livestatus module is more easily importable from Shinken.

See https://github.com/naparuba/shinken/pull/1505 for ref.

staute/shinken-mod-livestatus,shinken-monitoring/mod-livestatus,shinken-monitoring/mod-livestatus,staute/shinken-mod-livestatus,kaji-project/shinken-mod-livestatus,kaji-project/shinken-mod-livestatus