StoreUpdater to implement ContextAware

The context is derived from UpdateObserver together with the object graph
which is now generated from the context rather than assuming a valid
object contract(see line 127).

Definition of the PropertyChangeNotifier class has been moved into the DIC
for proper dependency handling.

Change-Id: I98b95b00f57e123923441c447f7b55e71f55f0a2