Issue: Value change notifications clarification

["Murray, Bryan P." <bryan.murray@hp.com>]

In WS-ResourceProperties section 6 2nd paragraph, the text implies that
a value change notification is to be sent only when a request to set the
property is received. This is further implied by the references to the
web service component of a WS-Resource needing to observe messages in
order to produce the notifications.

However, later on #4 (~line 1520) indicates that when a WS-Resource
observes a change it should create a notification. This implies that any
change, even those observed internally (such as metrics about a
resource), can produce a notification.

I recommend that the text be clarified to indicate that any change to
the value of a property can produce a notification if the property
supports notifications and someone is subscribed for changes to that
property.

Bryan