ecore: we need a different event for tracking the lifecycle of the main loop.

If the main loop is destroyed a lot of companion information might already
have been so relying on EFL_EVENT_DEL might be way to late in the shutdown
process. terminate will be triggered as soon as the process of shutting down
is started, so all the data are still valid and have not been destroyed yet.

src/lib/ecore/efl_loop.eo

@@ -137,6 +137,7 @@ class Efl.Loop (Efl.Object)
       poll,low; [[Event occurs multiple time every 15 minutes. The exact tick is undefined and could be adjusted system wide.]]
       pause; [[Called when the window is going not be displayed for some time]]
       resume; [[Called before a window get rendered after a pause event]]
+      terminate; [[Called before starting the shutdown of elementary]]
    }
    implements {
       Efl.Object.constructor;