Change storage.INode.add_subscription() to return a Failure when a subscription already exists. Added storage.INode.get_subscription() for retrieving the subscription state.
Change storage.INode.add_subscription() to return a Failure when a subscription
already exists.
Added storage.INode.get_subscription() for retrieving the subscription state.

--HG--
extra : convert_revision : svn%3Ae60b0d31-0b1b-0410-851a-a02d0c527677/trunk%40127

ralphm/idavoll