Static Pipeline is constructed with the help of AbstractServiceInstance and PipelineOrchestrator.

- Since we decided to implement the Static pipeline, there is no datapath requirement to keep a Director.
  Since the pipeline is static, the PipelineOrchestrator coordinages with the AbstractServiceInstance to program the direct path between the Tables
  without any involvement from the Concrete Service that is implemented on top of AbstractServiceInstance.
  Hence, this change removes Director table from the pipeline. But, the software design remains intact wherein the logic of pipeline datapath management
  still resides in AbstractServiceInstance, which the Concrete Service class need not be worried about.
- Implemented a sample L2RewriteService that extends from AbstractServiceInstance and registers itself with PipelineOrchestratorImpl through regular OSGi Service Registry

Change-Id: Ib27a795ebd428fc0a3b97aa3d18d825fe8427246
Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>
Merge "Static Pipeline is constructed with the help of AbstractServiceInstance and PipelineOrchestrator."