Subscribed item properties should be updated on the websocket

[wvhn]

SmarthomeNG supports subscribing item properties like e.g. myitem.property.last_change by a frontend via the monitor command on the websocket. The actual value of the item property is then sent with all regular items in the first answer. But while shNG later sends updates for the subscribed regular items, it does not send updates for item properties.

shNG should also send updates for the subscribed item properties, i.e. if an item is updated, check whether a property of that item has been subscribed and then update that, too.