Trigger current mode property change events

Each time the current mode property changes, handle the event similarly
to other event signal triggers substituting with a null message. When
the handler receives a null message, the property's value that triggered
the event is retrieved whether from the zone object or from dbus.

Tested:
    Triggered the use of alternative events based on thermal control
mode property state

Change-Id: Ibc663c3721c331393250bd32bda0d45cf0214f12
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
1 file changed