Add link messages for listing saves and listening for changes to the
list of saves for instances along with a table in the instance view page
showing the save list for the instance and a list-saves command to ctl.
Check if the instance status in the instanceStatusChanged event actually
changed and ignore the event if it didn't. This prevents bogus updates
from being pushed to control clients and plugins.
Provide the control link with the ability to subscribe to updates when
instance status and properties changes. This allows the web interface
to respond in real time to instance starts and stops that are triggered
from somewhere else.
Hornwitser