plugin XEP-0060: added node watching methods to bridge: new methods psNodeWatchAdd and psNodeWatchRemove allows to set a watch for the time of the session on one node, to have a signal called when something change on this node. This signal (psEventRaw) send raw data (raw XML), in opposition to psEvent which is there to send high level data (e.g. parsed blog data). Those method are primarely there to let frontends manage local cache for pubsub nodes.