Bug 1284: Fixed serialization of Augment Instance Identifier

Instance Identifier pointing to Augmentation, which pointed
to augmentation with leafs only, was not properly
serialized to DOM Instance Identifier and this caused
subscription for parent node.

Instance Identifier Codec was updated to detect
this case and use different algorithm to serialize
last argument.

Change-Id: Ie47ec7a5ebc86e10a7e1b3ddbc8921bf089466b2
Signed-off-by: Tony Tkacik <ttkacik@cisco.com>
Bug 1225: Added DataBroker and DataChangeListener test suite.

Change-Id: I53a06845024936253f576e5095b3d00c15a47e99
Signed-off-by: Tony Tkacik <ttkacik@cisco.com>